The tourism office has decided to allow companies to sell models of the town hall as souvenirs to visitors. They have decided that the guide price should be $2.50 per model for the first 1000 models, and $1.00 per model thereafter. The companies are allowed to vary their prices by up to 20% above or below the guide price. In which one of the following graphs does the shaded region represent the range of incomes that the companies can expect to receive for the models?