Explanation/Reference:
Explanation:
Ethical hackers should use tools that have the potential of affecting servers or services to provide a valid security test. These are the tools that a malicious hacker would use.
The first step before sending even one single packet to the target would be to have a signed agreement with clear rules of engagement and a signed contract. The signed contract explains to the client the associated risks and the client must agree to them before you even send one packet to the target range.
This way the client understands that some of the tests could lead to interruption of service or even crash a server. The client signs that he is aware of such risks and willing to accept them.
Incorrect Answers:
A: An organization should use ethical hackers who do not sell auditing, hardware, software, firewall, hosting, and/or networking services. An ethical hacking firm's independence can be questioned if they sell security solutions at the same time as doing testing for the same client.
B: Testing should be done remotely to simulate external threats. Testing simulating a cracker from the Internet is often one of the first tests being done. This is to validate perimeter security. By performing tests remotely, the ethical hacking firm emulates the hacker's approach more realistically.
C: Ethical hacking should not involve writing to or modifying the target systems negatively. Proving the ability to write to or modify the target systems (without causing harm) is enough to demonstrate the existence of a vulnerability.
References:
Krutz, Ronald L. and Russel Dean Vines, The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, New York, 2001, p. 520

Positive Pressurization is a condition that exists when more air is supplied to a space than is exhausted, so the air pressure within that space is greater than that in surrounding areas. This condition can cause the situation mentioned above in the answer
B, you can make air go out of a room but not enter to it from the outside.

Those are the proper elements, you can use these two to achieve a covert channel. Low bits is not a term related to covert channels. Permissions are related to authentication, they do not achieve what the question wants. Also, classification is could not selected as a correct choice.
Check your official CISSP documentation to see what can be used as a covert channel.
"An active variation on eavesdropping is called Covert Channel eavesdropping, which consists of using a hidden unauthorized network connection to communicate unauthorized information. A Covert Storage Channel operates by writing information to storage by one process and then reading by using another process from a different security level. A Covert
Timing Channel signals information to another process by modulating its own resource use to affect the response time of another." Pg. 101 Krutz: The CISSP Prep Guide: Gold Edition

Explanation/Reference:
Explanation:
Because fiber-optic cable passes electrically non-conducting photons through a glass medium, it is resistant to Electromagnetic interference (EMI).
Incorrect Answers:
A: Microwaves are vulnerable to Electromagnetic interference (EMI).
C: Twisted pair cables are vulnerable to Electromagnetic interference (EMI).
D: Coaxial cables are vulnerable to Electromagnetic interference (EMI).