Question

the smooth muscle that controls the amount of light that enters the eye through the pupil is the __________. a choroids b suspensory ligament c ciliary muscle d iris

Explanation:

The iris is a smooth - muscle structure. It controls the size of the pupil, thereby regulating the amount of light that enters the eye. The choroids provide blood supply to the eye, the suspensory ligament is related to lens accommodation, and the ciliary muscle is mainly involved in changing the shape of the lens for focusing.

Answer:

D. iris