The correct answer is A. cost ascertainment, cost presentation, cost control.
Cost accounting is a branch of accounting that deals with the identification, measurement, accumulation, analysis, and reporting of costs. It is used to help managers make informed decisions about pricing, production, and other aspects of business operations.
Cost ascertainment is the process of identifying and measuring the costs of goods or services. This includes identifying the direct costs, such as materials and labor, and the indirect costs, such as overhead.
Cost presentation is the process of communicating the costs to managers and other decision-makers. This can be done in a variety of ways, such as through reports, graphs, and charts.
Cost control is the process of managing costs to ensure that they are within budget. This includes setting budgets, monitoring costs, and taking corrective action when necessary.
Option B is incorrect because tax planning, tax accounting, and financial accounting are all separate branches of accounting.
Option C is incorrect because presentation of accounting information, creation of policy, and day-to-day operation are all activities that are not typically associated with cost accounting.