Which one of the following does NOT explain the main difference between competitive (i.e., perfect competition) and non-competitive (e.g., monopoly, oligopoly, monopolistic competition) markets? O In competitive markets, sum of consumer surplus and producer surplus is maximized; in non-competitive markets, deadweight loss occurs. O In competitive markets, P>MC; in non-competitive markets, P=MC. O In competitive markets, MC is the same for all firms; in non-competitive markets, MC can be different among firms. O In competitive markets, efficiency is achieved in the long-run; in non-competitive markets, there is no efficiency even in the long-run