Which from following compounds the thermocol is obtained?

Identify product A in following reaction.

$$ \mathrm{C}_6 \mathrm{H}_5 \stackrel{+}{\mathrm{N}}_2 \mathrm{Cl}^{-} \xrightarrow{\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}} \mathrm{~A}+\mathrm{N}_2+\mathrm{CH}_3 \mathrm{CHO}+\mathrm{HCl} $$

Which among the following is vinylic halide?

Which of the following is Lewis base?