In the given reaction sequence,identify the correct reagents to prepare $A$ from $B$. The starting material is benzenesulfonic acid. The reaction with $\Delta / H_3O^+$ yields $B$ (benzene),and the reaction with $1. \text{Fused } NaOH, 2. H^+$ yields $A$ (phenol). Therefore,to prepare $A$ (phenol) from $B$ (benzene),the correct sequence of reagents is:

• A
  $Cl_2 / AlCl_3 ; Mg(THF) ; O_2 / H^{+}$
• B
  $HNO_3 + H_2SO_4 ; Sn + HCl ; NaNO_2 + HCl ; \text{Steam}$
• C
  $CH_3-CH=CH_2 / H^{+} ; O_2 / hv ; H^{+}$
• D
  All of these