'A' and 'B' are brothers. 'C' and 'D' are sisters. A's son is D's brother. How is B related to C?

• Father

• Brother

• Grandfather

• Uncle

D.

Uncle

Clearly, B is the brother of A; A's son is D's brother. This means D is the daughter of A. Since C and are sisters, C is also the daughter of A. So, B is the uncle of C.