Group the given figures into three classes using each figure only once.
A.
1,3,7 ; 2,4,6 ; 5,8,9
B.
1,4,6 ; 2,5,7 ; 3,8,9
C.
1,4,8 ; 2,5,6 ; 3,7,9
D.
1,4,8 ; 2,7,9 ; 3,5,6
Correct answer is C
1, 4, 8 contain similar elements (not equal in size) each divided into four parts and attached to each other.
2, 5, 6 contain three elements (two of which are similar) placed one inside the other.
3, 7, 9 contain one element inside the other, which may or may not be similar.