Which of the following is an example of a possible social engineering attack?

A.
A caller posing as a company vice president reports a problem with the username/password combination and requests a password reset.

B.
An unauthorized device is installed by a rogue administrator to capture network traffic.

C.
A co-worker watches a user enter the password and later the co-worker logs in as that user.

D.
An infected computer is used to send email containing viruses or spam.