Which of the following is correct as a Nernst equation for the given electrochemical cell ?
$Mg_{(s)}|Mg_{(aq)}^{2+}(0.1 \ M)||Cl_{(aq)}^{-}(0.1 \ M)|Cl_{2_{(g)}}(1 \ bar)|Pt_{(s)}$

• A
  $E_{cell} = E_{cell}^0 - \frac{0.059}{2} \log \frac{[Mg^{2+}][Cl^{-}]^2}{P_{Cl_2}}$
• B
  $E_{cell} = E_{cell}^0 - \frac{0.059}{2} \log \frac{[Mg^{2+}]}{[Cl^{-}]^2}$
• C
  $E_{cell} = E_{cell}^0 - \frac{0.059}{2} \log \frac{1}{[Mg^{2+}][Cl^{-}]^2}$
• D
  $E_{cell} = E_{cell}^0 - \frac{0.059}{2} \log [Mg^{2+}][Cl^{-}]^2$