Which, if any, of the following metals would be capable of acting as a sacrificial anode when used with an iron pipe?
Iron E°Fe = -0.44 V; all E° values refer to the standard M²⁺/M reduction potentials.

A. Cd, E° = -0.40 V
B. None of these metals would be capable of acting as a sacrificial anode with iron.
C. tin, Sn, E° = -0.14 V
D. chromium, Cr, E° = -0.74 V
E. cobalt, Co, E° = -0.28 V
F. copper, Cu, E° = 0.15 V