Therese plays lacrosse, but she has injured her ankle and has to take a few weeks off. She is finding that she has a lot of trouble sleeping since she is no longer practicing several days a week. What BEST explains this?

OPTIONS:

A.
She needs regular exercise to move oxygen through the blood.
B.
She clearly requires more exercise than most people to relieve stress.
C.
She is not releasing the endorphins that she used to, and that impacts her sleep.
D.
She is likely not maintaining the healthy habits that she did when she was practicing.

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