Explanation:

- The statement describes a situation where government borrows only to pay interest on past loans, not to cover new expenses.

- Primary deficit is calculated as fiscal deficit minus interest payments. If borrowing only covers interest, the primary deficit is zero.

- Option 1: Zero revenue deficit - This means revenue expenditure equals revenue receipts, not related directly to interest payments.

- Option 2: Zero primary deficit - This means the government’s borrowings only meet interest payments, with no additional borrowing for other expenses.

- Option 3: Zero fiscal deficit - This means there's no overall borrowing, so it's not relevant here.

- Option 4: Excess budget deficit - This is not a standard term in budget analysis.