Refer to the graph below for a purely competitive firm in the short run. The price of the firm's product is given by:

Firm X owns both tea and coffee plantations. It sells directly to the public. If the firm wants to increase the sales for the coffee, assuming that tea and coffee are substitutes, which of these strategies can it employ?

a. Increase the price for the tea b. Offer free expedited shipping on the coffee c. Advertise the tea more heavily d. Both A&B

Firms ________ in monopolistic competition due to product differentiation.

A. gain control over price B. have blocked entry C. have no control over price D. are limited in number