Final answer:
Platelets' primary function is a. hemostasis, as they participate in the process of blood clotting to stop bleeding from damaged blood vessels. They also produce growth factors important for tissue repair and healing.
Step-by-step explanation:
The primary function of platelets is a. hemostasis. Platelets participate in the stages leading up to coagulation of the blood to stop bleeding through damaged blood vessels.
The process of blood clotting involves the formation of a platelet plug and the promotion of clotting factors to form a fibrin clot. Platelets also play a role in the repair and healing of tissues by producing growth factors.