Answer - Blood Flow
Reasoning - Insulin is used through out and mainly in the blood stream which relies it to stabilize through out the flow of the body
B. To provide a standard way to orient body and enable precision when discussing human anatomy
Grooming can be the way you take care of yourself and carry yourself so I think the answer would be either B or D
I might be wrong, but I think it is myosin, actin, and sarcomere.