The correct option is D.
Fusion and fission reactions involve the generation of energy either by the coming together of atomic nuclei or by splitting apart of atomic nuclei. The amount of energy that is generated during fusion and fission process is very high and is in the range of kiloelectron volts (10^3 eV), megaelectron volts (10^6 eV) and gigaelectron volts (10^9 eV) per atom or particle.