Entry into a Perfectly Competitive Industry Will Occur in the Long

Entry into a perfectly competitive industry will occur in the long run until

A) economic profits are negative,but are exactly offset by positive accounting profits.
B) economic losses are incurred if firms follow "cutthroat" pricing policies.
C) normal accounting profits decline to zero.
D) economic profits decline to zero.
E) all managers of firms are perfectly satisfied with their salaries.