Which of the following products is an example of monopolistic competition? a. tap water c. books b. oranges d. bus tickets

Well, no one is really selling tap water, and bus tickets are a personal service. Between books and oranges, I would personally have to say books, if only because books publishers meet all of the four major factors that define monopolistic competition: large numbers of small firms, similar but not identical products sold, relative ease of entry and exit out of the industry, and extensive knowledge of sales factors. Hope this is helpful.