问题
单项选择题
In a perfectly competitive industry, the short-run supply curve for the market is the:（）
A. marginal cost curve above the average variable cost curve.
B. sum of the individual supply curves for all firms in the industry.
C. average variable cost curve above the marginal cost curve.
答案
参考答案：B
解析：
The short-run supply curve for a firm is its marginal cost curve above the average variable cost curve. The short-run supply curve of the market is the sum of the supply curves for all firms in the industry.