Toluene (excess) undergoes the following sequence of reactions:
$(i)$ $CrO_2Cl_2, CS_2$
(ii) $H_3O^+$
(iii) $NaHSO_3$
After filtration,a residue $(A)$ is obtained. This residue $(A)$ reacts with $dil. \ HCl$ to form compound $(B)$.
Identify the structures of residue $(A)$ and compound $(B)$ respectively.

• A
  Residue $(A)$: $C_6H_5CHO$,Compound $(B)$: $C_6H_5COOH$
• B
  Residue $(A)$: $C_6H_5CH(OCrOHCl_2)_2$,Compound $(B)$: $C_6H_5CHO$
• C
  Residue $(A)$: $C_6H_5CHO$,Compound $(B)$: $C_6H_5COONa$
• D
  Residue $(A)$: $C_6H_5CH(OH)SO_3Na$,Compound $(B)$: $C_6H_5CHO$