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

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.