Answer: Option (c) is the correct answer.
Step-by-step explanation:
Fusion reaction is defined as a reaction in which two small nuclei combine together and result in the formation of a large nuclei along with release of huge amount of energy.
For example, inside the Sun nuclear fusion takes place as four hydrogen nuclei are squeezed tightly with each other resulting in the formation of a helium atom.
As a result, some of the mass of hydrogen is converted into energy which released in the form of light.
is a nuclear fusion reaction.
On the other hand, a fission reaction is defined as a reaction in which a large nuclei splits into two small nuclei along with release of huge amount of energy.
For example,
is a nuclear fission reaction.
Thus, we can conclude that fusion of atoms process is best described by A.