After one $\alpha $ and two $\beta $ emissions

A plot of the number of neutrons $(N)$ against the number of protons ( $P$ )of stable nuclei exhibits upward deviation from linearity for atomic number, $Z>20$. For an unstable nucleus having $N / P$ ratio less than $1$ , the possible mode($s$) of decay is(are)

($A$) $\beta^{-}$-decay ( $\beta$ emission)

($B$) orbital or $K$-electron sasture

($C$) neutron emission

($D$) $\beta^{+}$-decay (positron emission)

During a negative beta decay

$\gamma$-decay occurs when

A nucleus with $Z = 92$ emits the following in a sequence: $\alpha ,\,{\beta ^ - },\,{\beta ^ - },\,\alpha ,\alpha ,\alpha ,\alpha ,\alpha ,{\beta ^ - },\,{\beta ^ - },\alpha ,\,{\beta ^ + },\,{\beta ^ + },\,\alpha $. The $Z$ of the resulting nucleus is

$_{90}^{232}Th$ an isotope of thorium decays in ten stages emitting six  $\alpha$-particles and four $\beta$-particles in all. The end product of the decay is