For apparel manufacturer Ann Taylor, Inc., classify each of the following costs as either a product cost or a period cost:
a. Sales commissions
b. Advertising expenses
c. Fabric used during production
d. Property taxes on factory building and equipment
e. Depreciation on sewing machines
f. Factory janitorial supplies
g. Depreciation on office equipment
h. Wages of sewing machine operators
i. Repairs and maintenance costs for sewing machines
j. Salary of production quality control supervisor
k. Salaries of distribution center personnel
l. Research and development costs
m. Oil used to lubricate sewing machines
n. Corporate controller’s salary
o. Utility costs for office building
p. Travel costs of salespersons
q. Factory supervisors’ salaries