For the Hydrogen/Oxygen Fuel-Cell, the Two Half Reactions of Which

For the Hydrogen/Oxygen fuel-cell, the two half reactions of which are shown below, the oxidant is found ___________ .
Reaction A 2 H₂ + 4 OH^- -----> 4 H₂O + 4 e^-
Reaction B O₂ + 2 H₂O + 4 e^- -----> 4 OH ^-

A) in the starting materials of Reaction A
B) in the starting materials of Reaction B
C) in the products of Reaction A
D) in the products of Reaction B
E) All of the above