The​ long-run average total cost curve is​ __________ and is found by using the​ ___________. A. ​upward-sloping; minimum point across all possible ATC curves for a given quantity. B. ​U-shaped; maximum points along the MC curve at various marginal revenues. C. ​upward-sloping; maximum points along the MC curve at various marginal revenues. D. ​U-shaped; minimum point across all possible ATC curves for a given quantity.