Which of the Following Statements Regarding Ordinary Chemical Reactions and Nuclear

Which of the following statements regarding ordinary chemical reactions and nuclear reactions is correct?

A) The identity of an atom never changes during a nuclear reaction.
B) The identity of an atom may not change during an ordinary chemical reaction.
C) There can never be a change in the total mass measured before and after a chemical reaction or a nuclear reaction.
D) The energy change associated with a chemical reaction is always much greater than that of a nuclear reaction.
E) The free energy of the universe always increases during nuclear reactions.