From the following items: X, Y, Z, A, and B, the selection rules are: 1) X and Y cannot be selected together. 2) If A is selected, then B must also be selected. 3) Z can be selected only if Y is not selected. Which of the following selections is valid?

C. X, Z

A, B, C, D, and E are five students. The following conditions are provided: A scored higher than B but lower than C. D scored lower than E but higher than A. Who scored the lowest?

B. B

A, B, C, D, and E are five friends. A is older than B but younger than C. D is younger than E but older than A. Who is the youngest?

B. B

In a group of items: P, Q, R, and S, the following rules apply: 1) P cannot be chosen if Q is chosen. 2) R must be chosen if S is not chosen. Which of the following selections is valid?

C. P, R

In a group of five friends - A, B, C, D, and E - the following conditions are given: A is taller than B but shorter than C. D is shorter than E but taller than A. Who is the tallest among them?

D. E