In a family, there are three siblings: X, Y, and Z. X is a lawyer, Y is a doctor, and Z is the youngest. If Z is not the lawyer, who is the oldest sibling?

A. X

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

Among A, B, C, and D, A is older than B but younger than C. D is younger than A. Who is the youngest?

D. D

In a cooking competition, Chef A finished before Chef B but after Chef C. Chef D finished last. What is the correct order of the chefs?

A. C, A, B, D

During a meeting, Person X spoke before Person Y but after Person Z. Person W spoke last. What is the correct order of speakers?

A. Z, X, Y, W