Explanation:
:
(A) (a) $\mathrm{n}=3, \quad l=1$
(b) $\quad \begin{aligned} & \Rightarrow \mathrm{n}=3, \quad l=2\end{aligned}$
(B) (a) $\quad \begin{aligned} & \Rightarrow 3 \mathrm{~d} \\ & \mathrm{n}=3, \quad l=2\end{aligned}$
(b) $\quad \begin{aligned} & \Rightarrow \mathrm{d} \\ & \mathrm{n}, 3, \quad l=2\end{aligned}$
(C) (a) $\quad \begin{aligned} & \Rightarrow \mathrm{d} \\ & \mathrm{n}=4, \quad l=2\end{aligned}$
$\Rightarrow 4 \mathrm{~d}$
(b) $\mathrm{n}=3, \quad l=2$ $\Rightarrow 3 \mathrm{~d}$