Identify the product ' B ' in the following sequence of recations.

$$\mathrm{CH}_3 \mathrm{Br} \xrightarrow{\mathrm{KCN}} \mathrm{~A} \xrightarrow{\mathrm{Na}_2 / \mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}} \mathrm{~B}$$

Which among the following has lowest boiling point?

Which of the following compounds does not undergo Williamson's synthesis?

Identify product ' B ' in following reaction.

$$\mathrm{CH}_3-\mathrm{I}+\mathrm{KCN} \longrightarrow \mathrm{~A} \xrightarrow[\substack{\mathrm{C}_2 \mathrm{H}_2 \mathrm{OH} \\}]{\mathrm{Na}} \mathrm{B} $$