Consider a firm making production decisions in the short run. Select the statement(s) that must be correct. Choose one or more: A. Average total cost will always exceed average variable cost. B. Average total cost cannot decline as output increases, at any level of output. C. Average fixed cost cannot increase with output, at any level of output. D. Average variable cost is always above the average fixed cost. E. Average variable cost cannot decline with output, at any level of output.