Choice "A" is correct. The report on the audit of the financial statements should describe the scope of the auditor's testing of compliance with laws and regulations and internal control over financial reporting, and should either present the results of those tests or refer to a separate report containing that information.
Choice "b" is incorrect. The CPA was engaged to audit financial statements in accordance with the Yellow Book, not to perform a performance audit.
Choice "d" is incorrect. The notes to the financial statements are a management representation and would not be used by the CPA to comply with requirements to either report or opine in conformity with Yellow Book requirements.
Choice "c" is incorrect. Governmental Auditing Standards require that the auditor describe the scope of the auditor's testing of compliance with laws and regulations and internal control over financial reporting and present the results of those tests as part of their report or in a separate report, not simply in a letter to the funding agency.