Question

what makes the pupil get larger or smaller?
a the amount of light or darkness
b the need to keep eyes warm in cold weather
c the need to see under water
d the amount of dirt or dust in the air

Explanation:

The pupil is the opening in the center of the iris. Its size changes mainly in response to the amount of light. In bright light (less darkness), the pupil constricts (gets smaller) to reduce the amount of light entering the eye. In dim light (more darkness), the pupil dilates (gets larger) to allow more light to enter for better vision. Options B, C, and D are not the main factors affecting pupil size. Keeping eyes warm, seeing underwater, or dirt - dust in the air are not the primary determinants of pupil size change.

Answer:

A. the amount of light or darkness