An older man tells a nurse. "The doctor says I have something wrong with my eyes, something called presbyopia. Can you explain why I have this? I was always fortunate to have good eyesight." The nurse formulates a response based on the knowledge that:

A. Presbyopia is an age-related condition in which the lens of the eye loses elasticity, making it difficult to focus on near objects—this is the most accurate explanation of the condition. B. Changes in the cornea that increase astigmatism can occur with age, but this is not the cause of presbyopia. C. A gray ring around the cornea (arcus senilis) is a normal age-related change but is unrelated to presbyopia. D. An increase in lens opacity refers to cataracts, which is a different condition that affects overall vision, not specifically near vision.