Which of the following statements is accurate about the Optimized web proxy cache mode on a Cisco WSA?

A. It caches negative responses.

B. It performs the least caching of all the modes.

C. It allows customization of caching parameters.

D. It performs the most caching of all the modes.

Explanation:
The Optimized web proxy cache mode on a Cisco Web Security Appliance (WSA) caches negative responses. The Cisco WSA Web Proxy feature can improve web traffic performance by intercepting and proxying web requests that use Hypertext Transfer Protocol (HTTP) and HTTP Secure (HTTPS). The Web Proxy feature can be set to one of the following four modes:

• Safe
• Optimized
• Aggressive
• Customized

Safe mode performs the least caching of all the modes and adheres closest to Request for Comments (RFC) 2616. Optimized mode performs moderate caching and adheres moderately to RFC 2616. In optimized mode, negative responses are cached as well as objects with a Last-Modified header and no specified caching time. Aggressive mode caches the most and adheres the least to RFC 2616. In aggressive mode, authenticated content, ETag mismatches, and content without a Last-Modified header are cached. In addition, the no-cache parameter is ignored. In customized mode, each parameter is configured individually by the administrator.

Reference: https://www.cisco.com/c/en/us/td/docs/security/wsa/wsa_12-5/User-Guide/b_WSA_UserGuide_12_5/b_WSA_UserGuide_11_7_chapter_0100.html