From the following items: P, Q, R, S, and T, the selection rules are: 1) P cannot be selected if Q is selected. 2) R must be selected if S is selected. 3) T can be selected only if P is not selected. Which of the following selections is valid?
Answer: D. R, S, T
R and S can be selected together, and since P is not selected, T can also be included.