George was recently fired from his job as an IT analyst at Pitts and Company in Dallas Texas. His main duties as an analyst were to support the company Active Directory structure and to create network polices. George now wants to break into the company network by cracking some of company Active Directory structure and to create network polices.

Which password cracking technique should George use in this situation?

A.
Brute force attack

B.
Syllable attack

C.
Rule-based attack

D.
Dictionary attack