An aqueous solution containing $1 \ M$ each of $Cu(NO_3)_2$,$AgNO_3$,$Hg_2(NO_3)_2$,and $Mg(NO_3)_2$ is electrolyzed using inert electrodes. Given the standard reduction potentials: $E^{\circ}_{Ag^+/Ag} = 0.80 \ V$,$E^{\circ}_{Hg_2^{2+}/2Hg} = 0.79 \ V$,$E^{\circ}_{Cu^{2+}/Cu} = 0.34 \ V$,and $E^{\circ}_{Mg^{2+}/Mg} = -2.37 \ V$. What is the correct order of deposition of metals at the cathode?

• A
  $Ag, Hg, Cu$
• B
  $Cu, Hg, Ag$
• C
  $Ag, Hg, Cu, Mg$
• D
  $Mg, Cu, Hg, Ag$