A Textbook Publisher Is in Monopolistic Competition

Multiple Choice

A textbook publisher is in monopolistic competition.If the firm spends nothing on advertising,it can sell no books at $100 a book,but for each $10 cut in price,the quantity of books it can sell increases by 20 books a day.The firm's total fixed cost is $2,400 a day.Its average variable cost and marginal cost is a constant $20 per book.If the firm spends $1,200 a day on advertising,it can increase the quantity of books sold at each price by 50 percent.If the publisher advertises,its profit maximizing price per book is

A) $40.
B) $50.
C) $60.
D) $70.
E) $20.