Question

which of the following factors of production is not variable in the long run?
a. all factors of production are variable in the long run.
b. property taxes on the assets of the firm
c. highly trained labor
d. the size of the firms plant

Explanation:

In economics, the long run is defined as a time period where a firm can adjust all its factors of production, meaning there are no fixed inputs. Property taxes, labor, and plant size can all be adjusted over the long run: a firm can relocate to change property taxes, hire/train more specialized labor, or modify plant size. By definition, all factors become variable in the long run.

Answer:

a. All factors of production are variable in the long run.