Which statement accurately reflects the role of an income statement?

The role of an income statement is primarily to summarize a company's operational performance over a specific period. This includes detailing the revenues generated and the expenses incurred during that time, which ultimately leads to the determination of net income or loss. The income statement provides insights into how well the company is performing in its core business activities, allowing stakeholders to evaluate profitability and operational efficiency.

While assessing cash position (as noted in one of the other options) is typically the function of a cash flow statement, and detailing asset purchases is more aligned with the balance sheet, the income statement focuses on a company's ability to generate profit through its operations. Additionally, while measuring revenue growth may be an aspect of the income statement, it does not encapsulate the full purpose of the document, which is more comprehensive in summarizing all operational performance indicators. Thus, the selected statement accurately captures the essence of the income statement's role in financial reporting.