Question

a ring - like band of muscle made of smooth muscle that will stop the flow of contents from one organ to another is known as what?
sphincter
valve
tendon
aponeurosis

Explanation:

A sphincter is a ring - like band of smooth muscle that controls the flow of contents between organs. A valve (in the context of the circulatory system) is a structure that prevents backflow of blood but is not made of smooth muscle in the same sense as described. A tendon connects muscle to bone. An aponeurosis is a sheet of fibrous tissue that connects muscles to other muscles or body parts.

Answer:

Sphincter