A firm producing agricultural fertilizers operates in a perfectly competitive wholesale market. The table below displays the firm's average cost (AC) and marginal cost (MC) at various weekly output levels.
| Output (tonnes per week) | Average Cost (£) | Marginal Cost (£) |
|---|---|---|
| 20 | 75 | 60 |
| 25 | 71 | 72 |
| 30 | 73 | 85 |
| 35 | 77 | 105 |
| 40 | 83 | 130 |
If the prevailing market price is £105 per tonne, at which of the following output levels will the firm maximize its total profit?
252525 tonnes per week
303030 tonnes per week
353535 tonnes per week
404040 tonnes per week
