NO.PZ2023061903000096
问题如下：
Q. A firm that increases its quantity produced without any change in per-unit cost is experiencing:选项：
A.economies of scale.
B.diseconomies of scale.
C.constant returns to scale.
解释：
C is correct. Output increases in the same proportion as input increases occur at constant returns to scale.
请问什么情况下规模经济不变
