The diagram shows a model of a nuclear change. An illustration of a nuclear reactor. There are 3 parallel lines sticking half out of the reactor labeled rods containing uranium. There are parallel rods in the reactor labeled neutron-absorbing material. It is labeled nuclear reactor.

Which nuclear process does the model illustrate?

nuclear fission, because nuclei combine
nuclear fission, because a nucleus breaks apart
nuclear fusion, because nuclei combine
nuclear fusion, because a nucleus breaks apart