(i) In a family of six persons A, B, C, D, E and F, there are two married couples.
(ii) D is grandmother of A and mother of B.
(iii) C is wife of B and mother of F.
(iv) F is the grand daughter of E.

How many male members are there in the family ?

Answer: D. Cannot be determined
Clearly, the sex of A cannot be determined.