The Figure Given Below Shows the Aggregate Demand and Supply

Multiple Choice

The figure given below shows the aggregate demand and supply curves of a perfectly competitive market.Figure 10.7

-In many cities, the market for cab services is monopolized. This monopoly arises because:

A) of economies of scale.
B) of government restrictions on the entry of new firms.
C) there is a limited space on the streets for taxis.
D) it protects the consumers from unscrupulous drivers.
E) of high fixed costs of entering the business.