While connected in a battery under standard conditions, label the reduction and oxidation for each pair of half cells noted below. Utilize a table of standard reduction potentials.
A. Sn4+(aq) + 2e----> Sn2+(aq) vs. Cu2+(aq) + 2e----> Cu (s)
B. Fe3+(aq) + e----> Fe2+(aq) vs. Pb2+(aq) + 2e----> Pb (s)
C. Ag+(aq) + e----> Ag (s) vs. Ni2+(aq) + 2e---> Ni (s)
D. Ag+(aq) + e----> Ag (s) vs. Au3+(aq) + 3e----> Au (s)