Which salt on heating does not give brown coloured gas is

• A

  ${\text{LiNO}}_{\text{3}}$

• B

  ${\text{KNO}}_{\text{3}}$

• C

  $\text{Mg}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$

• D

  $\text{Ba}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$