The table below shows the annual sales revenues of all six firms operating in a country's domestic smart-meter manufacturing market:
| Firm | Sales revenue (£m) |
|---|---|
| Firm P | 18.0 |
| Firm Q | 12.0 |
| Firm R | 9.0 |
| Firm S | 6.0 |
| Firm T | 3.0 |
| Firm U | 2.0 |
Which one of the following is the correct three-firm concentration ratio (CR3CR_3CR3) for this industry, and what does it suggest about the market structure?
CR3=54%CR_3 = 54\%CR3=54%; suggesting a monopolistically competitive market.
CR3=78%CR_3 = 78\%CR3=78%; suggesting a perfectly competitive market.
CR3=81.3%CR_3 = 81.3\%CR3=81.3%; suggesting a highly concentrated oligopoly.
CR3=78%CR_3 = 78\%CR3=78%; suggesting a highly concentrated oligopoly.
