The following reactions show the ${\mathrm{H}}_2{\mathrm{O}}_2$ behaviour in A and B reactions as

(1) $\mathrm{P}\mathrm{b}{\mathrm{S}}_{\left(\mathrm{s}\right)}+4{\mathrm{H}}_2{\mathrm{O}}_{2\left(\mathrm{a}\mathrm{q}\right)}\to \mathrm{P}\mathrm{b}\mathrm{S}{\mathrm{O}}_{4\left(\mathrm{s}\right)}+4{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}$

(2) $\mathrm{H}\mathrm{O}\mathrm{C}\mathrm{l}+{\mathrm{H}}_2{\mathrm{O}}_2\to {\mathrm{H}}_3{\mathrm{O}}^{+}+\mathrm{C}{\mathrm{l}}^{-}+{\mathrm{O}}_2$

• A

  oxidising in acidic medium and reducing in basic medium
• B

  reducing in acidic medium and oxidising in basic medium
• Correct answer
  C

  oxidising in acidic medium and reducing in acidic medium
• D

  reducing in acidic medium and oxidising in acidic medium

Hence, the correct answer is option: 'C'.