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

A. BROTHER

If M is the sister of N, and N is the father of O, what is the relationship of M to O?

A. AUNT

If M is the father of N and N is the son of O, what is the relationship of O to M?

C. WIFE

K is the daughter of L. M is the son of L. N is the wife of M. How is K related to N?

D. SISTER

If A + B means A is the brother of B, A - B means A is the sister of B, and A × B means A is the father of B, what is the relationship of C to D if C + D and D - C are true?

A. C IS D'S BROTHER