Which of the following statements is true of nuclear fusion?

It involves the splitting of an atom's nucleus.

It is the process currently used in most nuclear power plants.

It is a very endothermic process.

It occurs with very small atoms with low mass.

The answer to this question is letter "D" or the last item in the choices which is the nuclear fusion "It occurs with very small atoms with low mass".

The first statement, the second, as well as the third statement, is not true because these three statements are referring to nuclear fission.