It would be solid
hope this helps
The answer is; C
The radioisotopes in the interior of the earth are not in pure form and have many embedded impurities and are interspersed. Therefore when a neutron is released by a decaying atom, its chances of hitting another radioisotope atom (to continue the chain reaction) are lower than in a manmade nuclear reactor. This way, the radioactive chain reaction in the earth’s interior is not well sustained.
I believe that crude oil is derived from plants because it is made up of a liquid that is found beneath the earth surface so I guess you could go with plants it is not an animal or rock or salt so.. could be brainliest not 100% sure so if you are not sure go with your gut