In a given firm, the marginal product per hour worked for a skilled worker is twice as much as it is for an unskilled worker. Skilled workers earn $20 per hour, and unskilled workers earn $8 per hour. Based on this information, the firm should increase the:

A.Salary of skilled workers to attract more of them.

B.Use of skilled workers or decrease the use of unskilled workers.

C.Use of unskilled workers or decrease the use of skilled workers.