The table below details the economic profit and entry barriers of four different firms in an economy.
| Firm | Long-run Economic Profit | Barriers to Entry |
|---|---|---|
| A | Positive | High |
| B | Positive | Low |
| C | Zero | High |
| D | Zero | Low |
Which one of the firms, A, B, C or D, is most likely to operate in a perfectly competitive market?
Firm A
Firm B
Firm C
Firm D
