问题
单项选择题
At the equilibrium levels of output and price in a competitive industry without taxes:（）
A. consumer surplus is maximized.
B. producer surplus is maximized.
C. the sum of producer and consumer surplus is maximized.
答案
参考答案：C
解析：
At competitive equilibrium the sum of consumer and producer surplus is at its maximum level Neither consumer nor producer surplus is necessarily at a maximum at the equilibrium output and price. Which surplus is larger or smaller depends on the elasticity of supply and demand.