A fish in an aquarium with flat sides looks out at a hungry cat. To the fish, the distance to the cat appears to be

The distance of the cat will appear farther than it really is

Explanation:

The index of refraction of water is more than that of air. Light rays from the cat  are refracted towards the normal at the surface and diverge outwards. This extends the virtual position of the cat, putting in a place farther than it really is.

d is the correct answer

close lines strong magnet less close weaker