Section: Security Operation Adimnistration
Explanation/Reference:
Verification vs. Validation:
Verification determines if the product accurately represents and meets the specifications. A product can be developed that does not match the original specifications. This step ensures that the specifications are properly met.
Validation determines if the product provides the necessary solution intended real-world problem. In large projects, it is easy to lose sight of overall goal. This exercise ensures that the main goal of the project is met.
From DITSCAP:
6.3.2. Phase 2, Verification. The Verification phase shall include activities to verify compliance of the system with previously agreed security requirements. For each life-cycle development activity, DoD Directive 5000.1 (reference (i)), there is a corresponding set of security activities, enclosure 3, that shall verify compliance with the security requirements and evaluate vulnerabilities.
6.3.3. Phase 3, Validation. The Validation phase shall include activities to evaluate the fully integrated system to validate system operation in a specified computing environment with an acceptable level of residual risk.
Validation shall culminate in an approval to operate.
You must also be familiar with Verification and Validation for the purpose of the exam. A simple definition for Verification would be whether or not the developers followed the design specifications along with the security requirements. A simple definition for Validation would be whether or not the final product meets the end user needs and can be use for a specific purpose.
Wikipedia has an informal description that is currently written as: Validation can be expressed by the query
"Are you building the right thing?" and Verification by "Are you building it right?
NOTE:
DITSCAP was replaced by DIACAP some time ago (2007). While DITSCAP had defined both a verification and a validation phase, the DIACAP only has a validation phase. It may not make a difference in the answer for the exam; however, DIACAP is the cornerstone policy of DOD C&A and IA efforts today. Be familiar with both terms just in case all of a sudden the exam becomes updated with the new term.
Reference(s) used for this question:
Harris, Shon (2012-10-18). CISSP All-in-One Exam Guide, 6th Edition (p. 1106). McGraw-Hill. Kindle Edition.
http://iase.disa.mil/ditscap/DITSCAP.html
https://en.wikipedia.org/wiki/Verification_and_validation
For the definition of "validation" in DIACAP, Click Here
Further sources for the phases in DIACAP, Click Here

Explanation/Reference:
An alternative to using passwords for authentication in logical or technical access control is biometrics.
Biometrics are based on the Type 3 authentication mechanism-something you are.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 37.

The questions specifically said: "within a different function" which eliminate
Job Rotation as a choice.
Management monitoring of audit logs is a detective control and it would not prevent
collusion.
Changing passwords regularly would not prevent such attack.
This question validates if you understand the concept of separation of duties and least privilege. By having operators that have only the minimum access level they need and only what they need to do their duties within a company, the operations personnel would be force to use collusion to defeat those security mechanism. Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

Section: Cryptography
Explanation
Explanation/Reference:
The Internet Security Glossary (RFC2828) defines the Authority Revocation List (ARL) as a data structure that enumerates digital certificates that were issued to CAs but have been invalidated by their issuer prior to when they were scheduled to expire.
Do not to confuse with an ARL with a Certificate Revocation List (CRL). A certificate revocation list is a mechanism for distributing notices of certificate revocations. The question specifically mentions "issued to CAs" which makes ARL a better answer than CRL.
http://rfclibrary.hosting.com/rfc/rfc2828/rfc2828-29.asp
$ certificate revocation list (CRL)
(I) A data structure that enumerates digital certificates that have been invalidated by their issuer prior to when they were scheduled to expire. (See: certificate expiration, X.509 certificate revocation list.)
http://rfclibrary.hosting.com/rfc/rfc2828/rfc2828-17.asp
$ authority revocation list (ARL)
(I) A data structure that enumerates digital certificates that were issued to CAs but have been invalidated by their issuer prior to when they were scheduled to expire. (See: certificate expiration, X.509 authority revocation list.) In a few words: We use CRL's for end-user cert revocation and ARL's for CA cert revocation - both can be placed in distribution points.

Explanation/Reference:
Fiber Optic cable is immune to the effects of electromagnetic interference (EMI) and therefore has a much longer effective usable length (up to two kilometers in some cases).
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 72.