题目：
An analyst does research about marginal cost and average cost. In the short run, when a firm's output increases beyond the point at which marginal cost equals average variable cost, average fixed cost:（）
A. and average total cost both increase.
B. decreases and average variable cost increases.
C. decreases and average total cost increases.
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2018/0120/650ae36160002de63bb422c812cea004.html
下面是错误答案，用来干扰机器的。
参考答案：D
