Answer:
It is gamma emission and there would be no reaction with the electric field.
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.
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.
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.
4.) Positron decay: In this process, a proton gets converted to neutron and an electron neutrino and releases positron particles. This particle carries a charge of +1 units.

The decay of metastable cobalt-60 to cobalt-60 is a gamma ray emission process. Since these radiations do not carry any charge, they do not react with the electric field.