$\text{Toluene}$ $\xrightarrow{[O]} A$ $\xrightarrow{SOCl_2} B$ $\xrightarrow{NaN_3} C$ $\xrightarrow{\Delta} D$. What is $D$?

Which among the following has the highest boiling point?

Assertion $(A)$: Carboxylic acids are more acidic than Phenols.
Reason $(R)$: Resonance structures of carboxylate ion are equivalent,while resonance structures of phenoxide ion are not equivalent.

The reaction $R-CH_2-CH_2-COOH \xrightarrow[Br_2]{Red \ P} R-CH_2-CH(Br)-COOH$ is called as:

Which of the following substances reacts with $NH_3$ to form an amide or an amide-like derivative?

The most acidic of the following is