Which of the following net cell reactions occurs in a galvanic cell containing a cadmium electrode and a standard hydrogen electrode? Given: $E^0(Cd^{2+}(aq)|Cd(s)) = -0.403 \text{ V}$.

• A
  $H_2(g) + Cd^{2+}(aq) \rightarrow 2H^+(aq) + Cd(s)$
• B
  $Cd(s) + 2H^+(aq) \rightarrow Cd^{2+}(aq) + H_2(g)$
• C
  $2H_2(g) + Cd^{2+}(aq) \rightarrow 4H^+(aq) + Cd(s)$
• D
  $2Cd(s) + 2H^+(aq) \rightarrow 2Cd^{2+}(aq) + H_2(g)$