Section: Security Operation Adimnistration
Explanation/Reference:
Because the Reference Monitor is responsible for access control to the objects by the subjects it compares the security labels of a subject and an object.
According to the OIG: The reference monitor is an access control concept referring to an abstract machine that mediates all accesses to objects by subjects based on information in an access control database. The reference monitor must mediate all access, be protected from modification, be verifiable as correct, and must always be invoked. The reference monitor, in accordance with the security policy, controls the checks that are made in the access control database.
The following are incorrect:
Validation Module. A Validation Module is typically found in application source code and is used to validate data being inputted.
Clearance Check. Is a distractor, there is no such thing other than what someone would do when checking if someone is authorized to access a secure facility.
Security Module. Is typically a general purpose module that prerforms a variety of security related functions.
References:
OIG CBK, Security Architecture and Design (page 324)
AIO, 4th Edition, Security Architecture and Design, pp 328-328.
Wikipedia - http://en.wikipedia.org/wiki/Reference_monitor

Asymmetric digital subscriber line (ADSL) is designed to provide more bandwidth downstream (1 to 8 Mbps) than upstream (16 to 800Kb). DSL (Digital Subscriber Line) is a modem technology for broadband data access over ordinary copper telephone lines (POTS) from homes and businesses. xDSL refers collectively to all types of DSL, such as ADSL (and G.Lite), HDSL, SDSL, IDSL and VDSL etc. They are sometimes referred to as last-mile (or first mile) technologies because they are used only for connections from a telephone switching station to a home or office, not between switching stations.
xDSL is similar to ISDN in as much as both operate over existing copper telephone lines (POTS) using sophisticated modulation schemes and both require the short runs to a central telephone office
Graphic below from: http://computer.howstuffworks.com/vdsl3.htm

DSL speed chart
The following are incorrect answers:
Single-line Digital Subscriber Line (SDSL) deliver 2.3 Mbps of bandwidth each way. High-rate Digital Subscriber Line (HDSL) deliver 1.544 Mbps of bandwidth each way.
Very-high data-rate Digital Subscriber Line (VDSL) can deliver up to 52 Mbps downstream over a single copper twisted pair over a relatively short distance (1000 to 4500 feet).
Reference used for this question:
http://computer.howstuffworks.com/vdsl3.htm and http://www.javvin.com/protocolxDSL.html and 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 115).

Transport. The Layer 4 Transport layer supports the TCP and UDP protocols in the OSI Reference Model. This layer creates an end-to-end transportation between peer hosts. The transmission can be connectionless and unreliable such as UDP, or connection-oriented and ensure error-free delivery such as TCP.
The following answers are incorrect: Network. The Network layer moves information between hosts that are not physically connected. It deals with routing of information. IP is a protocol that is used in Network Layer. TCP and UDP do not reside at the Layer 3 Network Layer in the OSI Reference Model.
Presentation. The Presentation Layer is concerned with the formatting of data into a standard presentation such as ASCII. TCP and UDP do not reside at the Layer 6 Presentation Layer in the OSI Reference Model.
Application. The Application Layer is a service for applications and Operating Systems data transmission, for example HTTP, FTP and SMTP. TCP and UDP do not reside at the Layer 7 Application Layer in the OSI Reference Model.
The following reference(s) were/was used to create this question:
ISC2 OIG, 2007 p. 411 Shon Harris AIO v.3 p. 424

The Trusted Computer Security Evaluation Criteria book (TCSEC) is also referred to as the Orange book.

Security
Tamper-resistant microprocessors are used to store and process private or sensitive information, such as private keys or electronic money credit. To prevent an attacker from retrieving or modifying the information, the chips are designed so that the information is not accessible through external means and can be accessed only by the embedded software, which should contain the appropriate security measures.
Examples of tamper-resistant chips include all secure cryptoprocessors, such as the IBM 4758 and chips used in smartcards, as well as the Clipper chip.
It has been argued that it is very difficult to make simple electronic devices secure against tampering, because numerous attacks are possible, including:
physical attack of various forms (microprobing, drills, files, solvents, etc.) freezing the device applying out-of-spec voltages or power surges applying unusual clock signals inducing software errors using radiation measuring the precise time and power requirements of certain operations (see power analysis) Tamper-resistant chips may be designed to zeroise their sensitive data (especially cryptographic keys) if they detect penetration of their security encapsulation or out-of-specification environmental parameters. A chip may even be rated for "cold zeroisation", the ability to zeroise itself even after its power supply has been crippled.
Nevertheless, the fact that an attacker may have the device in his possession for as long as he likes, and perhaps obtain numerous other samples for testing and practice, means that it is practically impossible to totally eliminate tampering by a sufficiently motivated opponent. Because of this, one of the most important elements in protecting a system is overall system design. In particular, tamper-resistant systems should "fail gracefully" by ensuring that compromise of one device does not compromise the entire system. In this manner, the attacker can be practically restricted to attacks that cost less than the expected return from compromising a single device (plus, perhaps, a little more for kudos). Since the most sophisticated attacks have been estimated to cost several hundred thousand dollars to carry out, carefully designed systems may be invulnerable in practice.