Which action occurs during a nuclear change? a. no energy is involved in the reaction. b. the nucleus disappears. c. matter changes from one state to another. d. elements are created that differ from the reactants.

Nuclear reactions involves a change in the nucleus of the atom meaning that an element can entirely be converted into another element where the atom change in atomic number, mass and type.

Based on this, the correct answer is:
D. Elements are created that differ from the reactants.