Below you will find several activity drivers that can be used to assign indirect production costs (overhead) and general, selling, and administrative costs (period costs). For each of the activities, identify the appropriate driver that best approximates the activity, assuming the usage of resources across units or projects does not vary significantly.

Drivers:

U: Number of units or projects

D: Sales dollars

E: Number of employees

H: Number of labor or machine hours

C: Number of customers

a. Research and development

b. Product design

c. Shipping goods

d. Processing biweekly payroll

e. Warranty work

f. Post-sales service