Number of molecules/ions from the following in which the central atom is involved in $\mathrm{sp}^3$ hybridization is $\qquad$ $\mathrm{NO}_3^{-}, \mathrm{BCl}_3, \mathrm{ClO}_2^{-}, \mathrm{ClO}_3$

Question

Number of molecules/ions from the following in which the central atom is involved in \(\mathrm{sp}^3\)…