A black hat hacker is enumerating a network and wants to remain covert during the process. The hacker initiates a vulnerability scan. Given the task at hand the requirement of being covert, which of the following statements BEST indicates that the vulnerability scan meets these requirements? 

Answer options:

A. The vulnerability scanner is performing an authenticated scan.
B. The vulnerability scanner is performing local file integrity checks.
C. The vulnerability scanner is performing in network sniffer mode.
D. The vulnerability scanner is performing banner grabbing.

C