If a firm with a 10 percent market share merges with a firm with 15 percent of the market, by how much will the Herfindahl index change? The other firms have 40 percent, 15 percent, 10 percent, and 10 percent shares

A monopoly will arise if

A) two out of three of a town's pizzerias go out of business and only one new pizzeria opens. B) the town council passes a law granting Nick's Pizza the exclusive right to operate in that town. C) Papa Joe's Pizza becomes the largest pizza producer in town and Nick's Pizza stays small in size. D) several big pizza chains force several small pizzerias out of business. E) people decide they like pizza more than before so some pizzerias gain new customers.

In the above figure, if the market is unregulated, the equilibrium quantity is

A) 0 units. B) 70 units. C) 80 units. D) 100 units.