问题
单项选择题
Which of the following most accurately describes the relationship between the average total cost (ATC) curve and the average variable cost (AVC) curve The vertical distance between the ATC and AVC curves:（）
A. decreases as output increases.
B. increases as output increases.
C. remains constant as output increases.
答案
参考答案：A
解析：
The vertical distance between the ATC curve and AVC cost curve is average fixed cost, which decreases as output increases because more output is averaged over the same cost.