If M ÷ N means M is the daughter of N, M + N means M is the son of N, and M - N means M is the sister of N, what is the relationship of O if M ÷ N + O?

D. O IS N'S SON

If P is the father of Q, and Q is the son of R, what is the relationship of R to P?

B. WIFE

N is the grandfather of O. P is the father of O. How is N related to P?

B. FATHER

If A is the brother of B, and B is the sister of C, what is the relationship of A to C?

A. BROTHER

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

A. SON