Luke's Express Diner is the only place that sells burgers in a remote town in Arizona. As one of the​ long-time residents of the​town, Bertha Hayes contends that the burgers at​ Luke's are priced a bit too high. She claims that this is because the diner enjoys monopoly power in the town. Her​ neighbor, Ruth​ Ernes, disagrees that the diner is in a position to​ over-price products due to monopoly power because she herself knows a lot of people who​ don't like the food there.

Which of the following if true will weaken berthas argument?

a. The local government issues a limited number of restuarant licenses every year
b. the diner is highly rated by food critics and is a very popular eating place in the town
c. lukes express diner cut prices when the nearby coffeeshop cut prices on its sandwiches
d. monopolies in the area have damaged economic efficiency
e. lukes express diner recently increased the price of a burger due to an increase in meat prices, but burger sales remianed unchanged