Explanation/Reference:
Explanation:
Eavesdropping is not a countermeasure, it is a type of attack where you are collecting traffic and attempting to see what is being sent between entities communicating with each other.
Traffic analysis, which is sometimes called trend analysis, is a technique employed by an intruder that involves analyzing data characteristics (message length, message frequency, and so forth) and the patterns of transmissions (rather than any knowledge of the actual information transmitted) to infer information that is useful to an intruder.
Countermeasures to traffic analysis are similar to the countermeasures to cryptoattacks:
Padding messages. Creating all messages to be a uniform data size by filling empty space in the data.

Sending noise. Transmitting non-informational data elements mixed in with real information to disguise

the real message
Faraday cage can also be used as a countermeasure to traffic analysis as it prevents intruders from being able to access information emitted via electrical signals from network devices Incorrect Answers:
A: Padding messages (creating all messages to be a uniform data size by filling empty space in the data) is a countermeasure to traffic analysis.
C: Sending noise (transmitting non-informational data elements mixed in with real information to disguise the real message) is a countermeasure to traffic analysis.
D: Faraday cage (preventing intruders from being able to access information emitted via electrical signals from network devices) is a countermeasure to traffic analysis.
References:
Krutz, Ronald L. and Russell Dean Vines, The CISSP Prep Guide: Mastering the CISSP and ISSEP Exams, 2nd Edition, Wiley Publishing, Indianapolis, 2004, p. 334