|A) 1||B) 2|
|C) 3||D) 4|
B is the son of C but C is not the mother of B means C is the father of B. A is marned to C means A is the mother of B. F is brother of B means F is son of A and C. D is daughter of A means D is daughter of A and C
A is the mother and hence female. B is the son and hence male. C is the husband and hence male.
D in the daughter and hence female. E is the brother and hence male F is the son and hence male.
So, there are four males.