Question

which organ is a muscle that helps the lungs expand and contract? pancreas trachea diaphragm esophagus

Explanation:

The diaphragm is a dome - shaped muscle that plays a crucial role in the breathing process by contracting and relaxing to help the lungs expand and contract. The pancreas is an organ related to digestion and hormone production, the trachea is the windpipe for air passage, and the esophagus is for food passage to the stomach.

Answer:

C. diaphragm