Which one of the following statements is not one of three
conditions that must exist in order for it to make sense for a firm
to move from a base of direct labor of direct labor hours to a base
of direct labor cost in order to apply overhead?

A. The firm’s products must be similar in total cost.

B. The firm’s workers must not all be paid the same amount.

C. A positive relationship must exist between higher paid
workers and the level of manufacturing overhead.

D. The firm’s products must use different percentages of the
different wage scales.