The table below shows the annual sales revenue of the five firms operating in a regional passenger rail maintenance market:
| Firm | Annual Revenue (£ millions) |
|---|---|
| Apex Rail | 120 |
| Beacon Engineering | 90 |
| Crest Fleet | 60 |
| Driftwood Logistics | 20 |
| Express Track | 10 |
Based on these data, which one of the following is the correct calculation of the three-firm concentration ratio (CR3CR_3CR3) and the most accurate description of the market structure?
CR3=90%CR_3 = 90\%CR3=90%; the market is in perfect competition.
CR3=70%CR_3 = 70\%CR3=70%; the market is monopolistically competitive.
CR3=90%CR_3 = 90\%CR3=90%; the market is a highly concentrated oligopoly.
CR3=30%CR_3 = 30\%CR3=30%; the market is a contestable monopoly.
