Its Theresas first trip to New York City She goes and sees a
     It\'s Theresa\'s first trip to New York City. She goes and sees all the sights and finds herself walking through Times Square. She looks up and sees two billboards for the iPad and the BlackBerry tablet. Since Theresa is an excellent AP Economics student, she immediately realizes that these two different companies are  monopolistic competition because of product different and extensive advertising  monopolistic competition because there are many firms in the market  monopolistic competition because there are no barriers to enter the market  perfect competition because these same thing  oligopolistic because so few companies produce these types of products 
  
  Solution
(A) monopolistic competition because of product differentiation and extensive advertising.
Explanation:- Monopolistic competition is that situation of market wherein there are many sellers of the product, but the product of each seller is a bit different from the products of other sellers. This product differentiation manifests itself in terms of quality, shape, brand, colour, durability, trademark, different services and facilities offered to the consumers etc.

