To what does covert channel eavesdropping refer?

A.
Using a hidden, unauthorized network connection to communicate
unauthorized information

B.
The use of two-factor passwords

C.
Nonbusiness or personal use of the Internet

D.
Socially engineering passwords from an ISP

Explanation:
The correct answer is “Using a hidden, unauthorized network connection to communicate
unauthorized information”. A Covert Channel is a connection intentionally
created to transmit unauthorized information from inside a
trusted network to a partner at an outside, untrusted node.
Answer “Socially engineering passwords from an ISP” is called masquerading.