Which of the Following Is the Reaction That Occurs at the Cathode

Which of the following is the reaction that occurs at the cathode of a button battery?

A) 2MnO₂(s) + 2NH₄⁺(aq) + 2e^? ? Mn₂O₃(s) + 2NH₃(aq) + H₂O(l)
B) I₂(s) + 2e^? ? 2I^?(LiI)
C) 2NiO(OH) (s) + 2H₂O(l) + 2e^? ? 2Ni(OH) ₂(s) + 2OH^?(aq)
D) PbO₂(s) + $\mathrm { HSO } _ { 4 } ^ { - }$ (aq) +3H⁺(aq) +2e ^- ?PbSO₄(s) +2H₂O(l)
E) HgO(s) + H₂O(l) + 2e^? ? Hg(l) + 2OH^?(aq)