Market or Monopoly Power Leads to Market Failure Because

Market or monopoly power leads to market failure because

A) price exceeds marginal revenue,which causes the profit-maximizing firm to under-produce the good or service.
B) price exceeds marginal revenue,which causes the profit-maximizing firm to over-produce the good or service.
C) when MR = MC in profit-maximizing equilibrium,the value of the last unit produced is less than the marginal cost of producing the last unit.
D) firms with market power have no incentive to produce on their expansion paths.