The Table Above Shows the Current Costs for a Firm

The table above shows the current costs for a firm to advertising on the radio, television, and newspaper.
-Refer to the table above. If at the current advertising level, A = $10,000, B = $15,500, and C = $7,800, to maximize profit, which of the following should the firm do?

A) The firm should decrease its advertising on the radio and increase its advertising in newspapers.
B) The firm should decrease its advertising on the radio and decrease its advertising in newspapers.
C) The firm should decrease its advertising on the television and increase its advertising in newspapers.
D) The firm should increase its advertising on the television and decrease its advertising in newspapers.