An aromatic compound (A), on treatment with a saturated solution of sodium bisulphite, produced a solid crystalline product. (A) gave a compound (B) and a sodium salt of an aromatic monobasic acid (C ) on treatment with alkali. (B) contained 77.8% C and 7.4% H and rest, oxygen. The sodium salt on distillation with soda lime gave benzene. If (B) may be oxidised with `KMnO_(4)` to (C ), find the structural formulae of (A), (B) and (C )

Explanation

To solve the problem systematically, we will follow these steps:

### Step 1: Determine the empirical formula of compound (B)

Given that compound (B) contains:
- 77.8% Carbon (C)
- 7.4% Hydrogen (H)
- The rest is Oxygen (O)
...