Find $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ in the following reactions :
$\mathrm{NH}_{3}+\mathrm{A}+\mathrm{CO}_{2} \rightarrow\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}$
$\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}+\mathrm{H}_{2} \mathrm{O}+\mathrm{B} \rightarrow \mathrm{NH}_{4} \mathrm{HCO}_{3}$
$\mathrm{NH}_{4} \mathrm{HCO}_{3}+\mathrm{NaCl} \rightarrow \mathrm{NH}_{4} \mathrm{Cl}+\mathrm{C}$
Correct Option: , 4
$2 \mathrm{NH}_{3}+\underset{(\mathrm{A})}{\mathrm{H}_{2} \mathrm{O}}+\underset{2}{\mathrm{CO}_{2}} \longrightarrow\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}$
$\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}+\mathrm{H}_{2} \mathrm{O}+\underset{(\mathrm{B})}{\mathrm{CO}_{2}} \longrightarrow 2 \mathrm{NH}_{4} \mathrm{HCO}_{3}$
$\mathrm{NH}_{4} \mathrm{HCO}_{3}+\mathrm{NaCl} \longrightarrow \underset{\text { (C) }}{\mathrm{NaHCO}_{3}}+\mathrm{NH}_{4} \mathrm{Cl}$