A and B are brothers, C and D are sisters, A's son is D's brother. How is B related to C?
Explanation
If A’s son is the brother of D, it means A and D are children of A. D is the daughter of A.If D is the daughter of A, it means C and D both sisters are the daughter of A.A and B are brothers, which means A’s children are nephews of B, and B is the Uncle of A’s children.