Answer and explanation

Correct answer: D. becomes smaller as the circular muscles of the iris contract

  1. Step 1: A smaller pupil reduces the amount of light entering the eye and protects the retina.
Answer
becomes smaller as the circular muscles of the iris contract.
Why not the others: becomes larger as the radial muscles of the iris contract: this happens in dim light. becomes smaller: the lens does not change the size of the pupil. stays the same size as the retina controls the light: the iris adjusts the pupil size in bright light.

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