The Entry of New Firms into a Perfectly Competitive Market

The entry of new firms into a perfectly competitive market in the long run is most likely the result of

A) temporarily above-normal profit,despite the presence of barriers to entry
B) continued above-normal profit,despite the presence of barriers to entry
C) temporarily above-normal profit,combined with the absence of barriers to entry
D) continued above-normal profit,combined with the absence of barriers to entry
E) either temporarily or continued above-normal profit,despite the presence of barriers to entry