What is the production​ function? The production function is the relationship between A. the output produced by a firmthe output produced by a firm and the minimum​ long-run average cost of production. B. returns to scalereturns to scale and economies of scopeeconomies of scope. C. the output produced by a firmthe output produced by a firm and its cost of production. D. the inputs employed by a firm and the maximum output it can produce with those inputs. E. the output produced by a firm in the short run and in the long run.