Question

What is the key function of sphincters found along the digestive system?

A)They selectively allow and stop passage of partially digested food.
 B)They control and direct the quantity of food passing through the digestive organs and prevent backward movement of partially digested food.
 C)They improve the muscular strength of the organs involved in digestion.

Answer 1

Option A) is correct as I have seen this in my book

Answer 2

If I'm right I'd say They control and direct the quantity of food passing through the digestive organs and prevent backward movement of partially digested food. Hope it's helpful.