The mastery hypothesis: the mere fact that they are exercising makes patients feel like they have achieved something, cheering them up much as learning a new hobby or achieving a certain goal might cheer them up.
That sounds like B to me.
Lack of calcium Would be your answer
Answer:
Concentric contractions cause muscles to shorten, which creates strength. Eccentric contraction causes the muscles to elongate in response to greater reaction forces.
Explanation: