Which Statement Correctly Describes What Happens During Inspiration

Which statement correctly describes what happens during inspiration?

A) The external intercostal, pectoralis minor, and sternocleidomastoid muscles contract to expand the rib cage and the diaphragm contracts to flatten its dome shape.
B) The external intercostal, pectoralis major, and sternocleidomastoid muscles contract to expand the rib cage and the diaphragm contracts to flatten its dome shape.
C) The external intercostal, pectoralis major, and sternocleidomastoid muscles contract to expand the rib cage and the diaphragm relaxes to flatten its dome shape.
D) The external intercostal and sternocleidomastoid muscles contract to expand the rib cage and the diaphragm contracts to flatten its dome shape.