# Decomposition of $NaCl\rightarrow x+y$.They are

$\begin{array}{1 1}(a)\;Na^++Cl^-\\(b)\;Na^-+Cl^-\\(c)\;Na^++Cl^+\\(d)\;Na^-+Cl^-\end{array}$

$NaCl\rightarrow Na^++Cl^-$.
Hence $x+y\Rightarrow Na^++Cl^-$.
Hence (a) is the correct answer.