The hybridisation of orbitals of N atoms in $NO_3^-,NO_2^+$ and $NH_4^+$ are respectively

Question

$\begin{array}{1 1}(a)\;sp,sp^2,sp^3&(b)\;sp^2,sp,sp^3 \\(c)\;sp,sp^3,sp^2&(d)\;sp^2,sp^3,sp\end{array}$