Which of the following is NOT obtained when a mixture of methyl chloride and n-propyl chloride is treated with sodium metal in dry ether?

Identify the reagent $$\mathrm{A}$$ in the following conversion.

Alkyl halide $$\stackrel{A}{\longrightarrow}$$ Alkyl nitrite

Which among the following compounds is NOT prepared by Sandmeyer's reaction ?

Which among the following compounds undergoes SN$$^2$$ reaction fastly ?