Session services located in the Transport Layer both segment and reassemble the data from upper-layer applications and unite it onto the same data stream, which provides end-toend data transport services and establishes a logical connection between the sending host and destination host on a network. Pg. 82 Krutz: The CISSP Prep Guide.

In answer "Context-dependent", access is determined by the context of the decision as opposed to the information contained in the item being accessed. The latter is referred to as content-dependent access control. In content- dependent access control, for example, the manager of a department may be authorized to access employment records of a department employee, but may not be permitted to view the health records of the employee.
* The term positive in access control refers to positive access rights, such as read or write. Denial rights, such as denial to write to a file, can also be conferred upon a subject.
* Information flowdescribes a class of access control models. An informa- tion flow model is described by the set consisting of object, flow policy, states, and rules describing the transitions among states.

Transport Layer Security (TLS) provides for security between the
content server on the Internet and the WAP gateway. (Answer "Between the WAP gateway and the content server" is, thus, incorrect.) Similarly, WTLS provides security between the WAP
mobile device (client software) and the WAP gateway. Since WAP
cannot interface directly with the Internet, all WAP information has
to be converted to HTTP in the WAP gateway to enable it to exchange
information with the Internet content servers. The simple block diagram illustrates these concepts.
Exhibit:

image024
A vulnerability occurs since data encrypted with wireless protocols
has to be decrypted in the WAP gateway and then re-encrypted
with the Internet protocols. This process is reversed when data flows
from the Internet content servers to the WAP client. Thus, the information is vulnerable while it is in the decrypted state on the WAP gateway. This condition is known as the WAP Gap. In order to
address this issue, the WAP Forum has put forth specifications that
will reduce this vulnerability and, thus, support e-commerce applications.
These specifications are defined in WAP 1.2 as WMLScript
Crypto Library and the WAP Identity Module (WIM). The
WMLScript Crypto Library supports end-to-end security by providing
for cryptographic functions to be initiated on the WAP client from
the Internet content server. These functions include digital signatures originating with the WAP client and encryption and decryption of data. The WIM is a tamper-resistant device, such as a smart card, that
cooperates with WTLS and provides cryptographic operations during
the handshake phase.
The WAP Forum is also considering another alternative to providing
the end-to-end encryption for WAP. This alternative, described in
WAP specification 1.3, is the use of a client proxy server that communicates authentication and authorization information to the wireless network server.
*Answer "Between the Internet and the content server" is incorrect since the content server is on the Internet side of the communication and answer "Between the WAP content server and the WAP client" assumes a direct interface between the content server and the client without going through the necessary Internet and wireless protocols.

Sesame is an authentication and access control protocol, that also supports communication confidentiality and integrity. It provides public key based authentication along with the Kerberos style authentication, that uses symmetric key cryptography. Sesame supports the Kerberos protocol and adds some security extensions like public key based authentication and an ECMA-style Privilege Attribute Service.
The users under SESAME can authenticate using either symmetric encryption as in Kerberos or Public Key authentication. When using Symmetric Key authentication as in Kerberos, SESAME is also vulnerable to password guessing just like Kerberos would be. The Symmetric key being used is based on the password used by the user when he logged on the system. If the user has a simple password it could be guessed or compromise. Even thou Kerberos or SESAME may be use, there is still a need to have strong password discipline.
The Basic Mechanism in Sesame for strong authentication is as follow:
The user sends a request for authentication to the Authentication Server as in Kerberos, except that SESAME is making use of public key cryptography for authentication where the client will present his digital certificate and the request will be signed using a digital signature. The signature is communicated to the authentication server through the preauthentication fields. Upon receipt of this request, the authentication server will verifies the certificate, then validate the signature, and if all is fine the AS will issue a ticket granting ticket (TGT) as in Kerberos. This TGT will be use to communicate with the privilage attribute server (PAS) when access to a resource is needed.
Users may authenticate using either a public key pair or a conventional (symmetric) key. If public key cryptography is used, public key data is transported in preauthentication data fields to help establish identity. Kerberos uses tickets for authenticating subjects to objects and SESAME uses Privileged Attribute Certificates (PAC), which contain the subject's identity, access capabilities for the object, access time period, and lifetime of the PAC. The PAC is digitally signed so that the object can validate that it came from the trusted authentication server, which is referred to as the privilege attribute server (PAS). The PAS holds a similar role as the KDC within Kerberos. After a user successfully authenticates to the authentication service (AS), he is presented with a token to give to the PAS. The PAS then creates a PAC for the user to present to the resource he is trying to access.
Reference(s) used for this question: http://srg.cs.uiuc.edu/Security/nephilim/Internal/SESAME.txt and KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 43

The original answer was C however this is incorrect for this case. SLA and standby are good ideas but in this case B is right. "A software escrow arrangement is a unique tool used to protect a company against the failure of a software developer to provide adequate support for its products or against the possibility that the developer will go out of business and no technical support will be available for the product....Under a software escrow agreement, the developer provides copies of the application source code to an independent third-party organization. The third party then maintains updated backup copies of the source code in a secure fashion. The agreement between the end user and the developer specifies "trigger events", such as the failure of the developer to meet terms of a service level agreement (SLA) or the liquidation of the developer's firm." - Ed Tittle CISSP Study Guide (sybex) pg 550