31. Correct statements about the binding energy of a nucleus include which of the following?
I. It is the energy needed to separate the nucleus into its individual protons and neutrons.
II. It is the energy liberated when the nucleus is formed from the original nucleons.
III. It is the energy equivalent of the apparent loss of mass of its nucleon constituents.
A) I only
B) III only
C) I and II only
D) I, II, and III