P, Q, R and S are four statements. Relation between these statements is as follows.

I. If P is true, then Q must be true.

II. If Q is true, then R must be true.

III. If S is true, then either Q is false or R is false.



Which of the following must be true?

A

If P is true, then S is false

B

If S is false, then Q must be true

C

If Q is true, then P must be true

D

If R is true, then Q must be true