An inorganic salt $(A)$ is decomposed on heating to give two products $(B)$ and $(C)$. Compound $(C)$ is a liquid at room temperature and is neutral to litmus,while the compound $(B)$ is a colourless neutral gas. Compounds $(A)$,$(B)$ and $(C)$ are:

• A
  $NH_4NO_3, N_2O, H_2O$
• B
  $NH_4NO_2, NO, H_2O$
• C
  $CaO, H_2O, CaCl_2$
• D
  $Ba(NO_3)_2, H_2O, NO_2$