问题
单项选择题
The short-run supply curve for a firm under perfect competition:（）
A. is its average variable cost curve.
B. is its average variable cost curve above marginal revenue.
C. is its marginal cost curve above average variable cost.
答案
参考答案：C
解析：
The supply curve for a firm under perfect competition is its marginal cost curve above average variable cost. As long as price exceeds AVC, the firm will produce up to the quantity where MC =Price, which is also MR in this case.