The Marginal Product of a New Worker Is 80 Units

Multiple Choice

The marginal product of a new worker is 80 units and the marginal expense of a new worker is $800.The marginal product of hiring current workers another hour is 10 units and the marginal expense of hiring current workers another hour is $12.If the firm needs extra hours of work (assuming the work could be done by either the new or current workers) ,it should

A) hire new workers.
B) hire current workers more hours.
C) be indifferent between hiring new workers or hiring current workers more hours.
D) not hire anyone for the added hours of work.