Protons are positive,
electrons are negative,
and neutrons are neutral.
In the nucleus, there are protons and neutrons, so the charge of a nucleus is positive.
Its D that so easy look at it
The light that makes up the image of the fish is refracted when it leaves the water and enters the air. Your brain thinks the light traveled straight, so the fish is not located in the direction from you that your brain thinks it is.
Friction but i may be wrong