How eyes adjust in order to focus the image of near or distant objects on retina?

Q. How eyes adjust in order to focus the image of near or distant objects on retina?

A.            The lens moves in or out according to the position of the object

B.            The retina moves in or out according to the position of the object

C.            The lens becomes thicker or thinner according to the position of the object

D.            The pupil gets larger or smaller according to the position of the object

Answer: The lens becomes thicker or thinner according to the position of the object