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

If P is true then Q must be true.

If Q is true then R must be true.

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

Then which of the following must be true?

- If P is true then S is false
- If S is false then Q must be true
- If Q is true then P must be true
- If R is true then Q must be true