The sun maintains its shine because of the

The correct answer is Option (3) → Fusion of Hydrogen

The energy of the sun comes from nuclear fusion in its core, where the temperature is about \( 1.5\times10^{7}\,\mathrm{K} \). In the proton-proton cycle four hydrogen nuclei combine to form one helium nucleus, releasing about 26.7 MeV.

    \( \displaystyle 4\,{}^{1}_{1}\mathrm{H} + 2e^{-} \rightarrow {}^{4}_{2}\mathrm{He} + 2\nu + 6\gamma + 26.7\,\mathrm{MeV} \)

NCERT (2026-27):
Nuclear Fusion – Energy Generation in Stars – “… Thermonuclear fusion is the source of energy output in the interior of stars.”

Nuclear Fusion – Energy Generation in Stars – “… The fusion reaction in the sun is a multi-step process in which the hydrogen is burned into helium. Thus, the fuel in the sun is the hydrogen in its core.”