When a firm is profit maximizing, ____?

Question

I. MRP = W

II. MRP = MC

III. MR = MC

IV. MR = MRP

Answer 1

all firms maximize profit when mr=mc...right?

Answer 2

A. I and III only

III. MR = MC is true and everybody knows it

I. MRP = W comes from MRP=MFC profit maximization condition (MRP - marginal revenue product; MFC - marginal factor cost) but MFC=Wage so this one is true too.

Answer 3

III. MR = MC

When Marginal Revenue is equal to Marginal Cost then Firm maximizes profit (in monopolistic markets).