问题
单项选择题
Which of the following is TRUE for a price-taker firm in long-run equilibrium when there are no barriers to entry（）
A. P=MC=ATC=MR.
B. P=AVC=MR.
C. AVC=TR=TＣ.
答案
参考答案：A
解析：
For a price - taker firm, long - run equilibrium is where P = MC = ATC. For price taking firms, P = MC. Competition eliminates economic profits in the long run so that P = ATC.