Q$08$: Inside a nucleus undergoing beta$-$plus decay, a proton $P^{+}$changes into a neutron $n^0$ and a positron $e^{+}$

$P^{+}{n}^0+e^{+}$

${?}_2^A{?}_{z-1}^{bet{a}^{+}}F$

In this process

A$.$ the mass of the proton is greater than the mass of the neutron.

C$.$ the mass of the proton is equal to the mass of the neutron.

B$.$ the mass of the proton is less than the mass of the neutron.

D$.$ the mass of the proton is equal to $($the mass of the neutron $+$ the mass of the positron$).$