In the scheme given below,$X$ and $Y$,respectively,are:
$\text{Metal halide} \xrightarrow{\text{aq. NaOH}} \text{White precipitate } (P) + \text{Filtrate } (Q)$
$P \xrightarrow[\text{heat}]{\text{aq. } H_2SO_4, PbO_2 (\text{excess})} X (\text{a coloured species in solution})$
$Q$ $\xrightarrow[\text{warm}]{\text{MnO(OH)}_2, \text{Conc. } H_2SO_4} Y (\text{gives blue-coloration with KI-starch paper})$

• A
  $CrO_4^{2-}$ and $Br_2$
• B
  $MnO_4^{2-}$ and $Cl_2$
• C
  $MnO_4^{-}$ and $Cl_2$
• D
  $MnSO_4$ and $HOCl$