A student listed the characteristics of chemical and nuclear reactions, Chemical and Nuclear Reactions

Which of these statements best explains the identity of Reaction D?
- it is a nuclear reaction because the atomic number remains the same when the number of valence electrons changes
- It is a nuclear reaction because the atomic number remains the same when the particles are emitted from the nucleus.
- It is a chemical reaction because the atomic number remains the same when the number of neutrons and protons changes
- It is a chemical reaction because the atomic number remains the same for all elements while a rearrangement of atoms through bonding occurs.