Question

what is released through nuclear fusion in stars?
○ energy
○ gas
○ mass
○ pressure

Explanation:

In stellar nuclear fusion, light atomic nuclei fuse into heavier ones. A small portion of the mass is converted into energy (per $E=mc^2$), which is emitted as radiation and heat. Gas, mass, and pressure are not the primary released product; mass is actually consumed (converted), gas is the reactant, and pressure is a condition for fusion, not the output.

Answer:

energy