When a Gamma Ray Is Emitted from an Unstable Nucleus

When a gamma ray is emitted from an unstable nucleus,

A) the number of neutrons and the number of protons drop by two.
B) the number of neutrons drops by one and the number of protons increases by one.
C) the number of protons drops by one and the number of neutrons increases by one.
D) there is no change in either the number of neutrons or the number of protons.
E) none of the given answers