Given below are four jumbled sentences. Out of the given options pick the one that gives their correct order.

P: Creating a relaxing bedroom environment is very important too, and this can be done using a calming, subtle fragrance.

Q: It is possible to retrain your brain to have a sound sleep.

R: This is possible if you make sure your room is undisturbed, quiet and dark.

S: Start by regulating the times you go to bed and get up.