Which element is nuclear fusion least likely to produce?

hydrogen, which has an approximate mass of 1

chlorine, which has an approximate mass of 35

argon, which has an approximate mass of 39

silicon, which has an approximate mass of 28

I know the answer is not B

The element nuclear fusion is least likely to produce is hydrogen, which has an approximate mass of 1. This is because nuclear fusion makes use of hydrogen wherein atoms of hydrogen are combined to form heavier elements. This means that hydrogen cannot combine to form hydrogen. The lightest element that fusion can form is helium (2).