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

A. SISTER

X is the father of Y. Y has a sister Z. What is Z's relation to X?

A. DAUGHTER

X is the father of Y. Y is married to Z. Z has a brother W. How is W related to X?

C. BROTHER-IN-LAW

M is the uncle of N. N is the daughter of O. How is O related to M?

C. SISTER-IN-LAW

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

A. SISTER