基礎econ-u04-d01
In the short run, which statement about factors of production is correct?
A. At least one factor is fixed✓ 答案
B. All factors are variable
C. All costs are zero
D. Every factor is owned by the firm
解說
The short run is defined by at least one fixed factor, such as plant size. In the long run all factors are variable, which is why the long-run average cost curve is drawn as an envelope of short-run curves.