Answer:
d.
Step-by-step explanation:
The term known as "Nuclear Fusion" is a very important concept in chemistry and it is studied mostly under the topic or aspect of Chemistry known as or called radioactivity. Nuclear Fusion is the kind of reaction in which two or more atomic nucleus combines to for bigger ones.
There is a saying that there is no life without nuclear fusion because it is the reaction that causes the stars to have light.
Option 'd' is correct. This is what happens in stars in order for light to be produced that is the inward movement of gravity and the outward movement of nuclear fusion.