After a company has standardized to a single operating system, not all servers are immune to a well-known OSvulnerability. Which of the following solutions would mitigate this issue?

A.
Host based firewall

B.
Initial baseline configurations

C.
Discretionary access control

D.
Patch management system

Explanation:
A patch is an update to a system. Sometimes a patch adds new functionality; in other cases, it corrects a bug in
the software. Patch Management can thus be used to fix security problems discovered within the OS thus
negating a known OS vulnerability.