Which one of the following sentences would best complete the last paragraph of the passage? A. By limiting consumers' choices, abuse of monopoly power reduces consumers' welfare, but monopoly alone can sometimes actually operate in the consumers' best interest. B. What is needed now is a set of related laws to deal with the negative impacts that monopoly itself has on consumers' ability to purchase products at reasonable cost. C. Over time, the antitrust laws have been very effective in ensuring competition and, consequently, consumers' welfare in the volatile communications and computer systems industries. D. By controlling supracompetitive prices and corresponding supracompetitive profits, the antitrust laws have, indeed, gone a long way toward meeting that objective. E. As noted above, the necessary restraints on monopoly itself have been left to the market, where competitive prices and economies of scale are rewarded through increased market share.