Mixed Concrete cannot be shipped farther than twenty-five miles because the concrete might harden in the truck. Citrus County Concrete Company is the only supplier of mixed concrete to customers within a thirty-mile radius. Citrus County Concrete is an example of which one of the following competitive structures?
a) Monopoly
b) Oligopoly
c) Monopolistic competition
d) Pure competition
e) Monopsony
Answer: a) Monopoly