Identify the reaction taking place at the anode during the electrolysis of molten $NaCl$.

• A
  $2 OH^{-} \rightarrow H_2O + \frac{1}{2} O_2 + 2 e^{-}$
• B
  $2 H^{+} + 2 e^{-} \rightarrow H_2$
• C
  $Na^{+} + 1 e^{-} \rightarrow Na_{(s)}$
• D
  $2 Cl^{-} \rightarrow Cl_{2(g)} + 2 e^{-}$