Answer
a. Mg can prevent corrosion of iron as it is present above Fe in the activity series.
b. Cr can prevent corrosion of iron as it is present above Fe in the activity series.
c. Cu cannot prevent corrosion of iron as it is present below Fe in the activity series.
Work Step by Step
Rusting of iron can be prevented if iron is coated with metals above Fe in activity series.
a. Mg can prevent corrosion of iron as it is present above Fe in the activity series.
b. Cr can prevent corrosion of iron as it is present above Fe in the activity series.
c. Cu cannot prevent corrosion of iron as it is present below Fe in the activity series.