Erika Erika Has Been Having Trouble with Sleep Lately. in Particular

Erika
Erika has been having trouble with sleep lately. In particular, she finds that her mind races with minor worries when she tries to go to sleep. When she does fall asleep, she doesn't tend to stay asleep for very long. One night, Erika has three glasses of wine before bed. She falls asleep easily that night, but even after eight hours of sleep, she wakes up feeling unrested. Erika talked to her friend Betsy about her sleep problems, and Besty invited Erika to join her for her weekly yoga class. Betsy claimed that yoga really helped her to sleep well. In the class, Erika learned how to do some basic meditation. That night, Erika tried some of the meditation techniques just before going to bed. She had a great sleep and woke up feeling much more refreshed than she had in weeks.
-What is the best explanation for why meditation might help Erika sleep more easily

A)  Meditation is associated with an increase in REM activity, which will make Erika feel more rested even when she is awake. 
B)  Meditation has been demonstrated to reduce physiological arousal, which may allow Erika to relax enough to fall sleep. 
C)  Meditation has very strong placebo effects, so even though it has no effect on the body Erika's expectations will allow her to fall asleep more easily. 
D)  Meditation is a state of consciousness that is nearly identical to slow-wave sleep, so it trains Erika's body to be ready for real sleep.