Answer: C. Nuclear fission
Step-by-step explanation:
Nuclear fission is the reaction in which the nucleus of a heavy atom, when bombarded with neutrons (or when capturing an incident neutron), becomes unstable and divides into two or more nuclei of lighter atoms, giving rise to a situation of greater stability. In this process that takes place in the atomic nucleus, neutrons, gamma rays and large amounts of energy are emitted.
Then, with this division a great release of energy occurs and the emission of two or three neutrons, other particles and gamma rays.
This means fission is a process in which energy is released by the separation of the components of the nucleous of the atom.
In other words:
Matter is converted to energy, and in the case of powew plants, in electric energy.