The following are costs associated with manufacturing firms, merchandising firms, or service firms:

a. Miscellaneous materials used in production

b. Salesperson's commission in a real estate firm

c. Administrators' salaries for a furniture wholesaler

d. Administrators' salaries for a furniture manufacturer

e. Freight costs associated with inventories of a grocery store

f. Office manager's salary in a doctor's office g. Utilities for the corporate offices of a toy manufacturer h. Line supervisor's salary for a clothing-manufacturing firm i. Training seminar for sales staff of a service firm j. Fuel used in a trucking firm k. Paper used at a printing business 1. Oil for machinery at a plastics manufacturing firm

$\mathrm{m}$. Food used at a restaurant n. Windshields used for a car manufacturer Classify the costs as (1) product or period, (2) variable or fixed, and (3) direct materials, direct labor, or manufacturing overhead. Write "not applicable (NA)" if a category doesn't apply.