From the diagram, D represents the demand curve for an agricultural commodity, while S1 shows the original supply curve. The government implements a buffer scheme to keep farm incomes at their starting level. If a bumper harvest shifts the supply curve to S2, what quantity would the government have to purchase from the farmers to add to the buffer stock?
- A1000 tonnes
- B2000 tonnes
- C3000 tonnes
- D4000 tonnes