Answer: kul just don’t add too much points or people will scam u so be carful
Explanation:
I'm pretty certain that it's a or b. C and D would be something that a surgean would wonder. Although, im most certain that it's B. Scientists are always asking how or about the causes of something
Images are focused by the lens onto the retina which is a face at the back of the eye upon which light sensitive cells (rods and cones) convert the incident light into electrical signals that are transmitted to the brain.
The fovea is a pit directly behind the lens on the retina that contains a concentration of light sensitive, closely packed cones (colour sensitive cells) and is responsible for sharp central vision.