Answer:
Sodium reacts with the oxygen in air. It reacts vigorously with oxygen and the moisture that is already present in the air and thus catches fire.
Answer is: C. nuclear fission.
Nuclear fission is a nuclear reaction or a radioactive decay where nucleus of atom split into smaller ligher nuclei.
Nuclear fission is exothermic reaction which release large amounts of energy (electromagnetic radiation or as kinetic energy, which heat reactors where fission reaction take place).
The answer & explanation for this question is given in the attachment below.
I am not sure what you are asking, but TT likely refers to the pure tall peas Mendel worked with.