Which of the following statements is included as a main financial statement?

The income statement is a primary financial statement that provides essential information regarding a company's financial performance over a specific period. It summarizes revenues, expenses, and profits or losses, making it a crucial tool for stakeholders, including investors, creditors, and management. The income statement helps in assessing the profitability of the entity, tracking income trends over time, and making informed business decisions based on the entity's operational efficiency.

The other options do not qualify as main financial statements. A tax return is primarily concerned with tax obligations and does not reflect the comprehensive financial activities of a company. A market analysis report focuses on market conditions and competitive landscape, which are external factors rather than internal financial performance. An operational budget outlines a company's planned expenditures but is not a financial statement in itself; it serves more as a financial planning tool to guide operations rather than provide a snapshot of financial performance.