Final answer:
The conclusion that follows in a single step from the given premises is S.
Step-by-step explanation:
The conclusion that follows in a single step from the given premises is S. The correct answer is option a. (S 2, 3, MP). In modus ponens, if premise 1 states that X is sufficient for Y and premise 2 states that X is true, then the conclusion (Y) necessarily follows. In this case, premise 2 states that T is true and premise 3 states that T, so the conclusion S follows. Therefore, option a is the correct answer.