Answer:
b. Rotate into a position (cocked) to bind to actin.
Explanation:
The cycle starts with the myosin strongly united to the actin (in absence of ATP). The union of ATP dissociates the myosin from the actin and the ATP hydrolysis induces a conformational change in the myosin. This change affects the neck region of the myosin, which acts like a lever arm displacing the head group of the myosin. The ADP and phosphate stay united to the myosin head, which unites to the actin filament in a new position, liberating the phosphate and releasing ADP. This way, the myosin head adopts again its initial conformation.