One Assumption of the Perfectly Competitive Model Is That of Free

One assumption of the perfectly competitive model is that of free entry.This assumption most directly leads to the implication that:

A) firms will spend significant amounts of money on advertising.
B) positive economic profits will only be possible for in the short run.
C) firms will compete on the basis of better service and amenities rather than price.
D) a single firm will emerge as the industry leader.