Which of the following changes occur when you walk out of bright sunshine into a poorly lit room?(a) the pupil becomes larger (b) the lens becomes thicker(c) the ciliary muscle relaxes (d) the pupil becomes smaller

(a) the pupil becomes larger

Explanation

When we walk out of bright sunshine into a poorly lit room, the changes that occur is the pupil becomes larger so that more light can enter the eye and make surroundings visible.

 Pupil is a hole in the middle of the iris, which appears black because the light that passes through it, gets absorbed by the retina and is not reflected back. Its function is to control the amount of light entering the eye with the help of the iris so that it can be focused on the retina to begin the process of sight.

In low-light conditions, the pupil expands or dilates, so that more light can reach the retina to improve night vision. 

In bright conditions, the pupil shrinks or constricts to limit light entering into the eyes, so that too much light can't cause glare and discomfort to the eye, and even can't damage to the lens and retina of the eye.