Can a user belong to multiple groups?

A group can contain many users. Can a user belong to multiple groups?

A.
Yes always

B.
No

C.
Yes but only if they are using two factor authentication

D.
Yes but only in VPC

Explanation:
A group can contain many users, and a user can belong to multiple groups.
http://docs.aws.amazon.com/IAM/latest/UserGuide/id_groups.html