Which of the following statements concerning corrosion is(are) true? For the false statements, correct them. 

a. Corrosion is an example of an electrolytic process.

b. Corrosion of steel involves the reduction of iron coupled with the oxidation of oxygen.

c. Steel rusts more easily in the dry (arid) Southwest states than in the humid Midwest states.

d. Salting roads in the winter has the added benefit of hindering the corrosion of steel.

e. The key to cathodic protection is to connect via a wire a metal more easily oxidized than iron to the steel surface to be protected.