Question

select the correct answer.
what is the fuel for the nuclear fusion reaction that occurs in the sun?
a. helium
b. oxygen
c. plutonium
d. hydrogen

Explanation:

The Sun's energy comes from nuclear fusion. The main reaction is the proton - proton chain, where hydrogen nuclei (protons) fuse. Helium is a product of this fusion (not fuel). Oxygen and plutonium are not involved in the Sun's core fusion reactions.

Answer:

D. hydrogen