Continuous authentication is a type of authentication that provides protection against impostors who can see, alter, and insert information passed between the claimant and verifier even after the claimant/verifier authentication is complete. These are typically referred to as active attacks, since they assume that the imposter can actively influence the connection between claimant and verifier. One way to provide this form of authentication is to apply a digital signature algorithm to every bit of data that is sent from the claimant to the verifier. There are other combinations of cryptography that can provide this form of authentication but current strategies rely on applying some type of cryptography to every bit of data sent. Otherwise, any unprotected bit would be suspect. Robust authentication relies on dynamic authentication data that changes with each authenticated session between a claimant and a verifier, but does not provide protection against active attacks. Encrypted authentication is a distracter. Source: GUTTMAN, Barbara & BAGWILL, Robert, NIST Special Publication 800-xx, Internet Security Policy: A Technical Guide, Draft Version, May 25, 2000 (page 34).

Explanation/Reference:
Multiplexers are devices that enable enables more than one signal to be sent out simultaneously over one physical circuit.
Source: KRUTZ, Ronald L & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page
118).

Section: Security Operation Adimnistration
Explanation/Reference:
An overt channel is a path within a computer system or network that is designed for the authorized transfer of data. The opposite would be a covert channel which is an unauthorized path.
A covert channel is a way for an entity to receive information in an unauthorized manner. It is an information flow that is not controlled by a security mechanism. This type of information path was not developed for communication; thus, the system does not properly protect this path, because the developers never envisioned information being passed in this way. Receiving information in this manner clearly violates the system's security policy.
All of the other choices are bogus detractors.
Reference(s) used for this question:
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 219.
and
Shon Harris, CISSP All In One (AIO), 6th Edition , page 380
and
Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (p. 378). McGraw-Hill. Kindle Edition.

Explanation/Reference:
This is a tricky question, the keyword in the question is Internal users.
There are two possible answers based on how the question is presented, this question could either apply to internal users or ANY anonymous/external users.
Internal users should always have a written agreement first, then logon banners serve as a constant reminder.
Banners at the log-on time should be used to notify external users of any monitoring that is being conducted. A good banner will give you a better legal stand and also makes it obvious the user was warned about who should access the system, who is authorized and unauthorized, and if it is an unauthorized user then he is fully aware of trespassing. Anonymous/External users, such as those logging into a web site, ftp server or even a mail server; their only notification system is the use of a logon banner.
References used for this question:
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 50.
and
Shon Harris, CISSP All-in-one, 5th edition, pg 873

Explanation/Reference:
SSL was developed Netscape Communications Corporation to improve security and privacy of HTTP transactions.
SSL is one of the most common protocols used to protect Internet traffic.
It encrypts the messages using symmetric algorithms, such as IDEA, DES, 3DES, and Fortezza, and also calculates the MAC for the message using MD5 or SHA-1. The MAC is appended to the message and encrypted along with the message data.
The exchange of the symmetric keys is accomplished through various versions of Diffie-Hellmann or RSA.
TLS is the Internet standard based on SSLv3. TLSv1 is backward compatible with SSLv3. It uses the same algorithms as SSLv3; however, it computes an HMAC instead of a MAC along with other enhancements to improve security.
The following are incorrect answers:
"EDI transactions" is incorrect. Electronic Data Interchange (EDI) is not the best answer to this question though SSL could play a part in some EDI transactions.
"Telnet transactions" is incorrect. Telnet is a character mode protocol and is more likely to be secured by Secure Telnet or replaced by the Secure Shell (SSH) protocols.
"Eletronic payment transactions" is incorrect. Electronic payment is not the best answer to this question though SSL could play a part in some electronic payment transactions.
Reference(s) used for this question:
Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 16615-16619). Auerbach Publications. Kindle Edition.
and
http://en.wikipedia.org/wiki/Transport_Layer_Security