The correct answer is: A. Financial accounting.
Financial accounting is the oldest branch of accounting. It is the process of recording, summarizing, and reporting financial information about a business or other organization. Financial accounting information is used by investors, creditors, and other stakeholders to make decisions about the organization.
Cost accounting is the process of identifying, measuring, and assigning costs to products, services, or activities. Cost accounting information is used by managers to make decisions about pricing, production, and other aspects of the organization’s operations.
Management accounting is the process of providing financial and non-financial information to managers to help them make decisions about the organization’s operations. Management accounting information is not typically used by external stakeholders.
None of these is the oldest branch of accounting.