Which of the following statements about the use of nuclear energy is true?
a.
nuclear energy cannot be used safely.
b.
nuclear fusion has no known useful applications.
c.
nuclear fission is currently more useful for producing energy than nuclear fusion.
d.
nuclear fusion has fewer safety risks than nuclear fission.

The correct answer is "Nuclear energy cannot be used safely".

Explanation:

There are two types of nuclear reactions: Nuclear fission and Nuclear fusion.

Nuclear fission: The nuclear energy is originated from the splitting of uranium atom. Uranium is a radioactive material.

Nuclear reactor controls the release of energy.

The by product of the nuclear generation is the radioactive waste in the nuclear power plant.

The radioactive material emits harmful radiation. If there is any leakage in the power plant. Then, it would lead to hazard. It would harmful for the health of the employees who are working there.

Therefore, the correct option is (a).

there is none because earth is stationary and flat.