Rob owns the only ice cream shop in the entire region. When he lowers his price, the shop attracts more customers, but its total revenue falls. Which of the following do we know about Rob?

a. He is a monopolist operating on the inelastic region of his demand curve.

b. He is a monopolist operating on the elastic region of his demand curve.

c. He will choose to lower his price in such a situation as it is more efficient.

d. He is a price taker.