In? economics, the short run is the time frame in which? ______ and the long run is the period of time in which? ______. A. the quantities of some factors of production are? variable; the quantities of all factors of production are fixed B. the quantities of all factors of production are variable but technology is? fixed; sunk costs are variable C. the quantities of all factors of production are? fixed; the quantities of all factors of production can be varied D. the quantities of some factors of production are? fixed; the quantities of all factors of production can be varied