Which of the following anions are easily removed from aqueous solution by precipitation?

• A

  ${\mathrm{Cl}}^{\ominus }$

• B

  ${\mathrm{SO}}_4^{2-}$

• C

  ${\mathrm{NO}}_3^{\ominus }$

• D

  ${{\mathrm{CO}}_3}^{2-}$