A nucleus X undergoes following transformation \(\begin{matrix} X \xrightarrow{ \ \ \ a \ \ \ \ } Y \\\ Y \xrightarrow[ \ \ 2\beta \ \ ]{} Z \end{matrix}\) then
1
X and Y are isotopes
2
X and Z are isobars
3
X and Y are isobars
4
X and Z are isotopes