Which of the following accurately describes how economists distinguish between the short run and the long run?

Which of the following accurately describes how economists distinguish between the short run and the long run? Select one: 0 a. The cost of resources is higher in the short run than in the long run. 0 b. There are increasing returns in the long run but diminishing returns in the short run. 0 c. In the short run, all resources are fixed, and in the long run, all resources are variable. 0 d. In the long run, all resources are variable, and in the short run, at least one resource is fixed