In the Long Run, a Profit-Maximising Firm in a Monopolistically

In the long run, a profit-maximising firm in a monopolistically competitive market operates at:

A) some point above its average total cost curve
B) the minimum point on its average total cost curve
C) some point along the upward-sloping portion of its average total cost curve
D) some point along the downward-sloping portion of its average total cost curve