All of the Sun's energy is produced in its core through:

a. fusion

c. Hydrolysis

b. fission

d. hydrogenation

The sun is made up primarily of hydrogen gas. The centre of the sun is called its core and is its hottest part. There is also a large amount of pressure at the Sun's core. The large amount of hydrogen in the sun's core are compressed and heated so much that the fuse together in a reaction known as nuclear fusion which converts the hydrogen atoms into helium. The by-product of this nuclear fussion is a vast amount of energy which is released from the sun to the solar system.