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