Given below are four jumbled sentences. Pick the option that gives their correct order. 
A. Creating a relaxing bedroom environment is very important too, and this can be done using a calming, subtle fragrance..
B. It is possible to retrain your brain to have a sound sleep. 
C. This is possible if you make sure your room is undisturbed, quiet and dark. 
D. Start by regulating the times you go to bed and get up.