What are the advantages of nuclear energy?

(N/A) The advantages of nuclear energy are as follows:
$(a)$ A large amount of energy is produced per unit mass.
$(b)$ It does not produce smoke, making it a clean source of energy.
$(c)$ The fission of one atom of uranium produces $10$ million times the energy released by the burning of one atom of carbon.
$(d)$ The fusion of four hydrogen atoms produces a huge amount of energy, approximately equal to $27 \, \text{MeV}$.