question 6\n3 tries left\nwhat part of the eye hardens as we age, thus causing many to suffer from…

Brief Explanations:

As people age, the lens of the eye loses its flexibility and hardens, leading to presbyopia, a condition where it becomes difficult to focus on close - up objects. The vitreous humor is a gel - like substance that fills the eye cavity, and rods and cones are photoreceptor cells in the retina, not related to the hardening that causes presbyopia.

Answer:

A. lens