A white salt is readily soluble in water and gives a colour less solution with a pH of about 9. The salt would be

• A

  ${\mathrm{NH}}_4{\mathrm{NO}}_3$

• B

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

• C

  ${\mathrm{CH}}_3{\mathrm{COONH}}_4$

• D

  ${\mathrm{CaCO}}_3$