A team of four players: X, Y, Z, and W must be selected based on the following criteria: 1) X cannot be selected if Y is selected. 2) Z must be selected if W is selected. Which of the following combinations is valid?
If M × N means M is the mother of N, N - O means N is the sister of O, and O + P means O is the brother of P, what is the relationship of M to P in the expression M × N - O + P?