A recently installed application update caused a vital application to crash during the middle of the

workday. The application remained down until a previous version could be reinstalled on the
server, and this resulted in a significant loss of data and revenue.
Which of the following could BEST prevent this issue from occurring again?

A.
Application configuration baselines

B.
Application hardening

C.
Application access controls

D.
Application patch management

Explanation:
Patch management is the process of maintaining the latest source code for applications and
operating systems by applying the latest vendor updates. This helps protect a systems from newly
discovered attacks and vulnerabilities. A part of patch management is testing the effects of vendor
updates on a test system first to ensure that the updates do not have detrimental effects on the
system, and, should the updates have no detrimental effects on the test systems, backing up the
production systems before applying the updates on a production system.