The colour of the solid produced by adding NH3 to a solution of HgCl₂ is

The reaction is 

$$\begin{gathered} {\mathrm{HgCl}}_2+2aq\cdot {\mathrm{NH}}_3⟶\mathrm{Hg}\left({\mathrm{NH}}_2\right)\mathrm{Cl}+{\mathrm{NH}}_4\mathrm{Cl} \\ \mathrm{White} \mathrm{ppt} \end{gathered}$$

Here, the correct option is A.