Question

The distinction between the short-run and the long-run for a perfectly competitive firm or a monopolist is that:

a. in the short-run all inputs are fixed whereas in the long-run no inputs are fixed

b. in the short-run all inputs are variable whereas in the long-run all inputs are fixed

c. in the short-run at least one input is fixed whereas in the long-run all inputs are fixed

d. in the short-run at least one input is fixed whereas in the long-run no inputs are fixed