Answer:
I think is C because if use clean instruments you avoid infections.
D sores, i’m pretty sure sores are common in a lot of sexual transmitted diseases
Some reminders are necessary:
Artery does not have valves, the blood pressure on it is very high, there is no risk of blood backflow, so it does not need valves
Arteries are vessels that transport blood from the heart to capillaries.
Veins are vessels that transport blood back to the heart from capillaries.
According to these reminders, you could conclude that:
A is false (no backflow in arteries)
C is false (no backflow in arteries)
D is false ( veins take blood to the heart)
so the right answer is B
At the distal end of the muscle