What is involved in a muscle contraction? A. Myofibrils in the muscle shorten and lengthen to make the muscle contract and

Question

What is involved in a muscle contraction? 
A. Myofibrils in the muscle shorten and lengthen to make the muscle contract and extend. 
B. Actin and myosin come in and out of the cell to make it thicker or thinner which changes its length. 
C. The gap junctions between the cells pull them closer together which shortens the muscle. 
D. The extra nuclei trigger nerves to stiffen the muscles and make them shorter.

Kunduz · Accepted Answer

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