All of the Following Are Characteristics of Monopolistic Competition EXCEPT

All of the following are characteristics of monopolistic competition EXCEPT:

A) the use of advertising to differentiate products
B) a relatively large number of sellers
C) each seller firm is not particularly concerned about the relationship between its individual actions and those of other firms in the industry.
D) collusive agreements which lead to the tendency for all firms in an industry to charge approximately the same price for a specific product over long periods of time.
E) each seller firm attempts to retain or increase its market share by differentiating its product from the output of other firms.