Which, If Any, of the Following Metals Would Be Capable

Multiple Choice

Which, if any, of the following metals would be capable of acting as a sacrificial anode when used with iron pipe? E°_Fe = −0.44 V; all E° values refer to the M²⁺/M half-cell reactions.

A) copper, Cu, E° = 0.15 V
B) cobalt, Co, E° = −0.28 V
C) chromium, Cr, E° = −0.74 V
D) tin, Sn, E° = −0.14 V
E) None of these metals would be capable of acting as a sacrificial anode with iron.