Which of the following correctly describe a firm's short run costs? Select all that apply. Group of answer choices Total cost (TC) is equal to fixed cost (FC) minus variable cost (VC). As output increases, average fixed cost (AFC) continually decreases. When marginal cost (MC) equals average variable cost (AVC), AVC is at its lowest value. When marginal product of labor (MPL) decreases, marginal cost (MC) falls. When marginal cost (MC) is above average total cost (ATC), ATC is increasing