European communism collapsed during the years

The major dilemma facing Boeing and Airbus is the

A) fact that neither will respond to the behavior of the other. B) certainty surrounding the reaction of each firm to the behavior of the other firm. C) fact that if each firm separately tries to maximize its profit, it might wind up with less profit that otherwise. D) competition from other firms that drives their economic profit to zero. E) fact that when they collude to maximize their profit, the other firm's profit might be larger than its profit.

Some years ago New York City imposed rent controls in an effort to provide housing at "fair" prices for as many people as possible. The result was a serious shortage of housing and deterioration of existing rental properties. How would an economist have described the result in terms of economic efficiency?