Nuclear fission is caused by the impact of:
A. Neutron
B. Proton
C. DeuteronD. Electron

Nuclear fission is mainly due to neutrons. Neutrons are the particles in an atom that has a neutral charge. They aren't positive like protons nor negative like neutrons. nuclear fission is a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller, lighter nuclei. The fission process often produces free neutrons and gamma photons and releases a very large amount of energy even by the energetic standards of radioactive decay.