Hydrogen peroxide oxidises ${\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{4-}\mathrm{to}\mathrm{ }{\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{3-}$ in acidic medium, but reduces ${\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{3-}\mathrm{to}{\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{4-}$ in alkaline medium. The other products formed are, respectively

• A

  ${\mathrm{H}}_2\mathrm{O}\mathrm{ }\mathrm{and}\mathrm{ }\left({\mathrm{H}}_2\mathrm{O}+{\mathrm{OH}}^{-}\right)$
• B

  $\left({\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2\right)\mathrm{ }\mathrm{and}\mathrm{ }{\mathrm{H}}_2\mathrm{O}$
• C

  $\left({\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2\right)\mathrm{ }\mathrm{and}\mathrm{ }\left({\mathrm{H}}_2\mathrm{O}+{\mathrm{OH}}^{-}\right)$
• Correct answer
  D

  ${\mathrm{H}}_2\mathrm{O}\mathrm{ }\mathrm{and}\mathrm{ }\left({\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2\right)$

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