The correct answer is A. Providing supplementary information as needed . Notes to financial statements are designed to give users additional information that supports, explains, and expands on the amounts shown in the main financial statements. They may include descriptions of accounting policies, contingencies, commitments, segment information, assumptions, and other disclosures necessary for fair presentation. FASB-related disclosure materials and accounting references describe notes as providing supporting or supplementary information for items presented in the statements.

Option C is partly true in a narrower sense because the notes often include a summary of significant accounting policies , but that is only one component of their broader purpose. Option B is incorrect because totals are summarized in the statements themselves, not mainly in the notes. Option D is also incorrect because the notes are not limited to financial statistics; they provide qualitative and quantitative disclosures that help users interpret the statements properly. Therefore, the best overall answer is that notes serve the purpose of providing supplementary information as needed to make the financial statements more complete, understandable, and decision-useful.