H⁺ ion concentration of water does not change by adding :

• A

  ${\mathrm{CH}}_3\mathrm{COONa}$

• B

  ${\mathrm{NaNO}}_3$

• C

  $\mathrm{NaCN}$

• D

  ${\mathrm{Na}}_2{\mathrm{CO}}_3$