For the reaction $2HI_{(g)} \rightleftharpoons H_{2(g)} + I_{2(g)}$,the equilibrium constant $K$ at room temperature is $2.85$,and at $698 \ K$ it is $1.4 \times 10^{-2}$. This indicates that:

• A
  $HI$ is an acidic compound.
• B
  $HI$ is very stable at room temperature.
• C
  $HI$ is less stable relative to $H_2$ and $I_2$.
• D
  $HI$ possesses resonance stability.