If Any of the Assumptions of Perfect Competition Are Violated

Multiple Choice

If any of the assumptions of perfect competition are violated,

A) supply-and-demand analysis cannot be used to study the industry.
B) graphs with flat demand curves cannot be used to study the firm.
C) graphs with downward-sloping demand curves cannot be used to study the firm.
D) there may still be enough competition in the industry to make the model of perfect competition usable.
E) one must use the monopoly model instead.