Nonverbal Reasoning Figure puzzle

Group the given figures into three classes using each figure only once.

A) 1,2,6 ; 3,4,7 ; 5

B) 1,3 ; 2,6 ; 4,5,7

C) 1,2,6,7 ; 3 ; 4,5

D) 1,3 ; 2,4,5 ; 6,7

Watch this space for answer in a week.