Answer:
C. Forced inhalation
Step-by-step explanation:
To understand the function of each muscle one has to remember the specific attachment sites to the bone. This muscle, as the name describes, attaches to the sternum, the clavicle and the mastoid apophysis. If the muscle contracts, this will produce a linear pull that will expand the thoracic cavity. Therefore, one can assume this muscle will have a crucial role in forced inhalation.