You are presented with the question "what involves the retina?" and the following answer choices: 
- gravity
 - disease
 - h2o
 - reacts
 - CO 2
 - digestion
 - painful
 - sight

Now knowing that sight is the ability to sense light, and the eye is the organ that senses light and inside the eye, at the back, is the retina, choose the best answer.


 

        sight 