If D is the mother of E and E is the daughter of F, how is D related to F?

B. WIFE

If G is the uncle of H and H is the son of I, how is G related to I?

B. BROTHER-IN-LAW

If A + B means A is the brother of B, and B - C means B is the sister of C, what is the relationship between A and C?

C. COUSIN

If D is the daughter of E and E is the sister of F, what is the relationship between D and F?

A. NIECE

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

C. BROTHER-IN-LAW