The source of the sun's heat is
a. nuclear disintegration.
b. nuclear separation.
c. nuclear fission.
d. nuclear fusion.

D. Nuclear fusion

Explanation:

Nuclear fusion is the process that occurs in the core of the Sun and that provides the energy that keeps it alive.

The type of nuclear fusion that occurs in the Sun is the hydrogen-helium fusion, in which four nuclei of hydrogen, after several processes, fuse into a nucleus of helium-4. The final mass of the helium-4 is slightly less than the total mass of the 4 nuclei of hydrogen, so part of the mass has been converted into energy, according to Einstein's relationship:

where m is the mass converted into energy and c is the speed of light. Since is a very huge number, a lot of energy is released during nuclear fusion.

photocells convert light energy to electricity

another example of kinetic energy would be,

kinetic energy   >     moving energy

answer   >   letter choice (c),   a hammer falling off a table.

hope that !                                         : )