Cost accounting is used for which of the following?

Cost accounting is primarily used for the justification of activities such as labor, equipment, and materials. This branch of accounting focuses on capturing all costs associated with a company's operations, providing detailed insights into costs incurred for various activities. By identifying where resources are allocated and how much they cost, cost accounting helps managers make informed decisions about pricing, budgeting, and financial planning.

For instance, if a public works manager is overseeing a construction project, cost accounting allows them to analyze labor costs, equipment utilization, and material expenditures to ensure that the project stays within budget. It helps in evaluating the efficiency and effectiveness of financial resources used in different segments of a project, which is essential for sound fiscal management.

In contrast, the other options do not align with the primary purpose of cost accounting. Justifying budgeting errors pertains more to financial reporting and analysis rather than directly to cost accounting. Assessing employee performance is typically handled through performance reviews and HR metrics, not through cost accounting methodologies. Analyzing market trends involves more external economic considerations and market research rather than internal cost analysis.