Which of the Following Is True

Which of the following is true?

A) Average cost pricing reduces the incentives for a monopolist to find ways to reduce its costs.
B) With natural monopoly, at the efficient level of output, losses will be incurred.
C) With natural monopoly, if regulators allow the firm to earn profits, there will be a welfare cost from producing too little of the good.
D) Government regulation of monopolies aims to achieve the efficiency of large-scale production, without permitting the producers to charge monopoly prices.
E) All of the above are true.