Identify the compounds [A], [B] and [C].

$\text{C}_6\text{H}_5\text{COOH} \xrightarrow{\text{PCl}_5} [\text{A}] \xrightarrow{+\text{H}_2\text{, } \text{Pd/BaSO}_4} [\text{B}] \xrightarrow{\text{KCN (alc), distil}} [\text{C}]$

$\text{H}-\text{C}\equiv\text{C}-\text{H} + \text{H}_2\text{O} \xrightarrow{\text{Hg}^{2+}/\text{H}_2\text{SO}_4} [\text{A}] \xrightarrow[\text{K}_2\text{Cr}_2\text{O}_7/\text{H}_2\text{SO}_4]{\text{[Oxidation]}} [\text{B}] \xrightarrow[(ii)\text{ dry distillation}]{\text{(i) } \text{Ca(OH)}_2} [\text{C}]$