Identify the compounds [A] and [B] in the reactions given below: (a) (b)

Identify the compounds [A] and [B] in the reactions given below: (a) $\text{C}_6\text{H}_6 \xrightarrow[\text{AlCl}_3(\text{anhy.})]{\text{CH}_3\text{Cl}} [\text{A}] \xrightarrow[\text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4]{[\text{O}]} [\text{B}]$ (b) $\text{CH}_3\text{-CHOH-CH}_3 \xrightarrow[\text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4]{[\text{O}]} [\text{A}] \xrightarrow{\text{NH}_2\text{OH}} [\text{B}]$