9708/13 Economics Oct Nov 2023 Online Test | Cambridge AS & A Level MCQ

In the diagram, D is the demand curve of an agricultural commodity and S is the initial supply curve.
The government promises to maintain farmers’ incomes at least at their initial level. The harvests in four subsequent years are shown by supply curves ${S_1}-{S_4}$.
In which years will the government not need to provide extra income to farmers?