The Trusted Computer System Evaluation Criteria (TCSEC) is a collection of criteria used to grade or rate the security offered by a computer system product. The
TCSEC is sometimes referred to as "the Orange Book" because of its orange cover. The current version is dated 1985 (DOD 5200.28-STD, Library No.S225,711) The TCSEC, its interpretations and guidelines all have different color covers, and are sometimes known as the "Rainbow Series".

Additional detective/administrative controls are job rotation, the sharing of
responsibilities, and reviews of audit records.
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 35

Explanation/Reference:
Explanation:
Proxies provide services through a single access point. Proxies can be installed in order to eavesdrop upon the data-flow between client machines and the web. All content sent or accessed - including passwords submitted and cookies used - can be captured and analyzed by the proxy operator.
Incorrect Answers:
B: A proxy can handle many services, not only a single service. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server and the proxy server evaluates the request as a way to simplify and control its complexity.
C: Proxies does not create a single point of failure.
D: Firewall proxies protect the base operating system.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 653