Answer: D. Neither the mass number nor the atomic number changes.
Step-by-step explanation:
1.) Alpha decay: In this process, alpha particles is emitted when a heavier nuclei decays into lighter nuclei. The alpha particle released has a charge of +2 units. The mass number of the radioisotope decreases by four and the The atomic number of the radioisotope decreases by two.

2.)Beta-decay: In this process, a neutron gets converted into a proton and an electron releasing a beta-particle. The beta particle released carries a charge of -1 units. The mass number remains same but the atomic number decreases by

3.) Gamma ray emission: in this process, an unstable nuclei gives off excess energy by a spontaneous electromagnetic process and releases
. These radiations does not carry any charge and are electrically neutral.
Neither the mass number nor the atomic number changes.
