An aromatic organic compound [A] with the molecular formula reduces Tollen’s reagent and undergoes…

An aromatic organic compound [A] with the molecular formula $\text{C}_7\text{H}_6\text{O}$ reduces Tollen’s reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives compound [B] which has the molecular formula $\text{C}_7\text{H}_6\text{O}_2$. On reaction with sodium bi-carbonate, compound [B] forms brisk effervescence. Identify the compounds [A] and [B]. Write the chemical reaction of compound [B] with sodium bi-carbonate.