Explanation:

- Government budgets typically cover a period of one year. This timeframe allows governments to plan for revenue and expenditures and make necessary adjustments annually.

- A five-year budget might be more strategically long-term but is not standard due to the dynamic nature of economic conditions and political landscapes.

- A two-year budget is uncommon as it might not offer the flexibility required to adapt to rapid changes.

- A ten-year budget is more of a forecast and not practical for detailed financial planning.