Which of the Following Is Not a Complication Encountered by Public

Which of the following is not a complication encountered by public utility regulatory commissions when they set rates?

A) It is difficult to determine the economic value of a public utility's fixed assets.
B) Public utilities typically engage in price discrimination, so many different rates must be determined.
C) The services provided by public utilities are typically jointly produced, so the allocation of costs among different services is difficult or impossible.
D) All of the above are problems that are encountered when regulatory commissions set rates.