What Is Being Used?

C.

The correct answer is C. Credentialed scan.

A credentialed scan is a type of vulnerability scan that uses the credentials of a user account with administrative privileges to access the target system and gather more detailed information about its patch status and configuration. By using administrative privileges, the scanner can access more information than it would be able to with a passive scan or a gray box vulnerability test.

In this scenario, the vulnerability scanner software has been installed on a server that is joined to the company domain. This implies that the server has access to the domain's Active Directory (AD) and can authenticate against it. By using a credentialed scan, the vulnerability scanner can use these credentials to access the patch posture of all the clients in the company's domain.

A passive scan, on the other hand, does not actively attempt to exploit vulnerabilities and does not require credentials to access the target system. It simply monitors network traffic and analyzes it for vulnerabilities. A gray box vulnerability test is a type of penetration test that simulates an attacker with partial knowledge of the target system's internal workings. The tester may have limited access to the system but not administrative privileges. Bypassing security controls means to circumvent security measures put in place to prevent unauthorized access.

Therefore, the best answer to this question is C. Credentialed scan, as it is the most appropriate type of scan to use in this scenario to gain visibility over the patch posture of all company clients.