Users who configure their passwords using simple and meaningful things such as pet names or birthdays are subject to having their account used by an intruder after what type of attack?

A.
Dictionary attack

B.
Brute Force attack

C.
Spoofing attack

D.
Random guess attack

E.
Man in the middle attack

F.
Change list attack

G.
Role Based Access Control attack

H.
Replay attack

I.
Mickey Mouse attack

Explanation:
A dictionary attack is an attack which uses a dictionary of common words to attempt to find the password of a user.
Reference: Security + (SYBEX) page 58