How does a certificate authority impact security?

How does a certificate authority impact security?
A . It validates client identity when communicating with the server.
B. It authenticates client identity when requesting an SSL certificate.
C. It authenticates domain identity when requesting an SSL certificate.
D. It validates the domain identity of the SSL certificate.

View Answer

Answer: D

Explanation:

A certificate authority is a computer or entity that creates and issues digital certificates. CA do not "authenticate" it validates. "D" is wrong because The digital certificate validate a user. CA –> DC –> user, server or whatever.

Reference: https://en.wikipedia.org/wiki/Certificate_authority