Use the following to answer questions 3-8: ​ Number of Workers Total Cost 0 1000 1 2200 2 3200 3 4000 4 4600 5 5000 6 5200 7 5600 8 6200 9 7000 10 8000 If hiring the 4th worker increases total product by 50 units and the price of each unit is $15,​ a. ​the firm should not hire the 4th worker as MRMC c. ​marginal revenue equals $150 d. ​the firm should not hire the 4th worker as MR