Section: Network and Telecommunications
Explanation/Reference:
In a full mesh topology, all network nodes are individually connected with each other, providing the highest availability. A partial mesh topology can sometimes be used to offer some redundancy.
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
106).

Explanation/Reference:
This is a requirement starting as low as C1 within the TCSEC rating.
The Orange book requires the following for System Integrity Hardware and/or software features shall be provided that can be used to periodically validate the correct operation of the on-site hardware and firmware elements of the TCB.
NOTE FROM CLEMENT:
This is a question that confuses a lot of people because most people take for granted that the orange book with its associated Bell LaPadula model has nothing to do with integrity. However you have to be careful about the context in which the word integrity is being used. You can have Data Integrity and you can have System Integrity which are two completely different things.
Yes, the Orange Book does not specifically address the Integrity requirements, however it has to run on top of systems that must meet some integrity requirements.
This is part of what they call operational assurance which is defined as a level of confidence of a trusted system's architecture and implementation that enforces the system's security policy. It includes:
System architecture
Covert channel analysis
System integrity
Trusted recovery
DATA INTEGRITY
Data Integrity is very different from System Integrity. When you have integrity of the data, there are three goals:
1. Prevent authorized users from making unauthorized modifications
2. Preven unauthorized users from making modifications
3. Maintaining internal and external consistancy of the data
Bell LaPadula which is based on the Orange Book address does not address Integrity, it addresses only Confidentiality.
Biba address only the first goal of integrity.
Clark-Wilson addresses the three goals of integrity.
In the case of this question, there is a system integrity requirement within the TCB. As mentioned above here is an extract of the requirements: Hardware and/or software features shall be provided that can be used to periodically validate the correct operation of the on-site hardware and firmware elements of the TCB.
The following answers are incorrect:
Security Testing. Is incorrect because Security Testing has no set of requirements in the Orange book.
Design Verification. Is incorrect because the Orange book's requirements for Design Verification include: A formal model of the security policy must be clearly identified and documented, including a mathematical proof that the model is consistent with its axioms and is sufficient to support the security policy.
System Architecture Specification. Is incorrect because there are no requirements for System Architecture Specification in the Orange book.
The following reference(s) were used for this question:
Trusted Computer Security Evaluation Criteria (TCSEC), DoD 5200.28-STD, page 15, 18, 25, 31, 40, 50.
Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition, Security Architecture and Design, Page 392-397, for users with the Kindle Version see Kindle Locations 28504-28505.
and
DOD TCSEC - http://www.cerberussystems.com/INFOSEC/stds/d520028.htm

Explanation/Reference:
If every one of the 100 clerks makes 1 error 12 times per year, it makes a total of 1200 errors. The Annnualized Rate of Occurence (ARO) is a value that represents the estimated frequency in which a threat is expected to occur. The range can be from 0.0 to a large number. Having an average of 1200 errors per year means an ARO of 1200

Explanation/Reference:
When a concealment cipher is used, every X number of words within a text, is a part of the real message.
The message is within another message.
A concealment cipher is a message within a message. If my other super-secret spy buddy and I decide our key value is every third word, then when I get a message from him, I will pick out every third word and write it down. Suppose he sends me a message that reads, "The saying, 'The time is right' is not cow language, so is now a dead subject." Because my key is every third word, I come up with "The right cow is dead." This again means nothing to me, and I am now turning in my decoder ring.
Concealment ciphers include the plaintext within the ciphertext. It is up to the recipient to know which letters or symbols to exclude from the ciphertext in order to yield the plaintext. Here is an example of a concealment cipher:
i2l32i5321k34e1245ch456oc12ol234at567e
Remove all the numbers, and you'll have i like chocolate. How about this one?
Larry even appears very excited. No one worries.
The first letter from each word reveals the message leave now. Both are easy, indeed, but many people have crafted more ingenious ways of concealing the messages. By the way, this type of cipher doesn't even need ciphertext, such as that in the above examples.
Consider the invisible drying ink that kids use to send secret messages. In a more extreme example, a man named Histiaeus, during 5th century B.C., shaved the head of a trusted slave, then tattooed the message onto his bald head. When the slave's hair grew back, Histiaeus sent the slave to the message's intended recipient, Aristagoros, who shaved the slave's head and read the message instructing him to revolt.
The following answers are incorrect:
A transposition cipher uses permutations.
A substitution cipher replaces bits, characters, or blocks of characters with different bits, characters or blocks.
Steganography refers to hiding the very existence of the message.
Source: WALLHOFF, John, CBK#5 Cryptography (CISSP Study Guide), April 2002 (page 1).
and also see:
http://www.go4expert.com/forums/showthread.php?t=415