A is the brother of B. C is the sister of B. D is the mother of A. How is D related to C?

B. MOTHER

X is the father of Y. Y is the daughter of Z. How is Z related to X?

B. WIFE

D is the mother of E. F is the brother of D. How is F related to E?

A. UNCLE

A is the sister of B. B has a son named C. How is C related to A?

A. NEPHEW

J is the son of K. L is the daughter of M, who is the sister of K. How is L related to J?

A. COUSIN