Identify whether each of the following costs of Granite Construction, Inc., would be classified as direct labor, direct materials, manufacturing overhead, or as selling, general, and administrative costs.

a. Hourly wages paid to backhoe operators.

b. Crankcase oil used in construction machinery.

c. PVC pipes used in a municipal sewer construction project.

d. Depreciation of bulldozers and other construction equipment.

e. Advertising costs.

f. Steel beams used in the construction of an office building.

g. Salaries paid to foremen responsible for supervising multiple construction projects.

h. Legal costs.

i. Gasoline used in trucks that haul construction equipment to various job sites.

j. Hourly wages paid to masons and carpenters.

k. Costs for accounting and tax services.

l. The CEOs salary.

m. Rivets, screws, nuts, and bolts.