Answer:
A. the head domain
Step-by-step explanation:
The head domain of the myosin interacts with the actin filaments. It binds to an active site on the actin producing an inclination of the myosin head and the hydrolysis of ATP. As a consequence of these changes, the myosin has the necessary energy and is in the right position, ready to move along the actin filament producing the contraction of the muscle.