If P is the uncle of Q and Q is the daughter of R, what is R's relation to P?

C. SISTER-IN-LAW

If M is the grandmother of N and N is the son of O, what is O's relation to M?

D. CHILD

If G is the son of H and H is the mother of I, what is the relationship of I to G?

D. SIBLING

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 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