The correct answer is Only B.

The primary deficit is a measure of a government's fiscal deficit excluding interest payments on its debt. It reflects the government's spending on goods and services and transfer payments, less its revenue from taxes and other sources. Understanding the relationship between fiscal deficit, interest payments, and the primary deficit is crucial.

• Fiscal Deficit: This is the difference between the government's total expenditure and its total revenue. It includes both spending on goods and services and interest payments.
• Interest Payment: This is the amount the government pays on its accumulated debt.
• Primary Deficit: This is calculated as: Fiscal Deficit - Interest Payments. A zero primary deficit indicates that the government's revenue from taxes and other sources is precisely covering its spending on goods and services and transfer payments, irrespective of the interest payments.

Let's analyze the options:

• A. Fiscal Deficit is zero: If the fiscal deficit is zero, it means the government's total expenditure equals its total revenue. However, this doesn't necessarily mean the primary deficit is zero because interest payments could still exist. The primary deficit could still be negative in the case of any interest payment.
• B. Interest payment is equal to Fiscal Deficit: If interest payments are equal to the fiscal deficit, then, by definition, the primary deficit is zero (Fiscal Deficit - Interest Payments = 0). This is because all government expenditure is accounted for by interest payments.

Therefore, only option B ensures a zero primary deficit.