To economists, the main difference between short run and long run is that:

Options

A. 1.In short run all inputs are fixed, while in long run all inputs are variable.
B. 2.In short run the firm varies all of its inputs to find the least cost combination of inputs.
C. 3.In short run, at least one of the firm's input level is fixed.
D. 4.When marginal product is at a maximum, average product equals marginal product, and total product is rising.

Answer

c