Question

which is the main fuel for nuclear fusion in all stars? (1 point) nitrogen helium carbon hydrogen

Explanation:

Nuclear fusion in stars begins with hydrogen nuclei fusing together to form helium, releasing energy. This is the primary fusion process that powers main-sequence stars, which make up the vast majority of stars. The other options are either products of fusion or used in later, more advanced stellar fusion stages, not the main initial fuel.

Answer:

hydrogen