If the generic production function =(K,) displays increasing returns to scale, the value of K is fixed in the short run, and the prices of all inputs are held constant, then
O the short-run average cost curve must be strictly decreasing.
O the long-run average cost curve must be strictly decreasing.
O the short-run and the long-run average cost curves will coincide.
O the long-run average cost curve must be strictly increasing.