The standard electrode potential for the reduction of Eu3+(aq) to Eu2+(aq) is ?0.43 V. Use the data in Appendix D to determine which of the following is capable of reducing Eu3+(aq) to Eu2+(aq) under standard-state conditions? (a) Sn2+(aq) (b) ln(s) (c) HCN(aq) (d) La(s)