In gamma ray emission from a nucleus
both the neutron number and the proton number change
there is no change in the proton number and the neutron number
only the neutron number changes
only the proton number changes
B.
there is no change in the proton number and the neutron number
In gamma-ray emission the energy is released from the nucleus, so that nucleus get stablished. The emission of gamma rays does not alter the number of protons or neutrons in the nucleus but instead of moving the nuleus from higher to lower energy state (unstable to stable).