Identify the products $$A$$ and $$B$$ in the reactions :

$$\begin{aligned} & R-X+\mathrm{AgCN} \longrightarrow A+\mathrm{Ag} X \\ & R-X+\mathrm{KCN} \longrightarrow B+\mathrm{KX} \end{aligned}$$

In carbylamine test for primary amines the resulting foul smelling product is

A secondary amine is

$$\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{Cl} \xrightarrow{\text { Alc. } \mathrm{NH}_3} A \xrightarrow{2 \mathrm{CH}_3 \mathrm{Cl}} B.$$ The product $$B$$ is