Answer:
The correct answer is:'by emitting a beta particle'.
Step-by-step explanation:
An atom with too many neutron relativity in comparison to number of proton will under radioactive decay by the means of beta-decay.
Beta-decay is a radioactive decay process in which a neutron gets converted to into proton and electron as a beta-particle with (-1)charge.
![_Z^A\textrm{X}\rightarrow _(Z+1)^A\textrm{Y}+_(-1)^0\beta](https://img.qammunity.org/2020/formulas/chemistry/middle-school/xra4h83wc9g8m6mnyjkdu6zsvpk9ti7p7b.png)
So , by emitting a beta-particle an atom with more number of neutrons than protons will under radioactive decay.