Which is a large, fan-shaped muscle that forms the chest and enables several arm movements?

The pectoralis is the large, fan-shaped muscle covering much of the chest. It helps move the arm, including bringing it forward and across the body, so “pectoralis” is the correct choice. The sternocleidomastoid moves the head, the biceps bends the elbow, and the transverse abdominis supports the abdomen.

AI-written and checked against the verified answer.