When Being Interviewed,a 50-Year-Old Patient Says That He Cannot See

When being interviewed,a 50-year-old patient says that he cannot see the newspaper as well as he used to.The nurse knows that vision changes from near to far occur because:

A) The ciliary muscle changes the pupil size.
B) The lens of the eye changes shape as the ciliary muscle contracts and relaxes.
C) Of nearsightedness.
D) Of a clouding of the vitreous humor.