Final answer:
Most of the energy released by nuclear fission is in the form of gamma rays, rather than alpha, beta, or X-rays.
Step-by-step explanation:
The question being asked is about the forms of energy released by nuclear fission. Nuclear fission releases large amounts of energy, primarily in the form of heat, light, and especially gamma radiation. Therefore, amongst the provided options, the most accurate is that most of the energy released by nuclear fission is in the form of gamma rays (b). Fission involves a heavy nucleus splitting into two smaller nuclei and a few neutrons, with a release of energy due to the mass difference. This energy is most prominently observed as gamma radiation, which is a form of high-energy, penetrating electromagnetic radiation.