Which of the Following Statements Concerning the Long-Run Average Cost

Which of the following statements concerning the long-run average cost (LRAC) curve is correct?

A) The LRAC curve represents the least-cost input combination of inputs for producing each level of output.
B) The LRAC curve is derived from a series of short-run marginal cost curves.
C) The short-run cost curve at the minimum point of the LRAC curve represents the least-cost plant size for all levels of output.
D) As output increases, the amount of capital employed by the firm is held constant along the LRAC curve.