C.
The energy produced by the Sun comes from nuclear fusion reactions.
Explanation
during formation of the solar system the centrifugal force of the sun caused it to collapse on it's self initialising nuclear fusion.
It’s B the cu looses its 2 and passes it to the NH3 that needs a bracket to separate them. The NH3 doesn’t loose its 3 because it’s already a compound!
Hope this helps!
Compounds. They both have more than one element in them
