Which of the following accurately describes the minimum point of the average total cost curve for a perfectly competitive firm? Assume that it is earning positive economic profit.

a)The intersection of the average total cost curve and the average variable cost curve

b) The profit-maximizing point of production

c) The intersection of the average total cost curve and the marginal cost curve

d) The point at which demand changes from its elastic to inelastic range

e) The point at which marginal cost equals marginal revenue