Final answer:
The cost management subsystem in question is the cost accounting information system. It helps managers track and control costs, and aids in strategic financial decision-making.
Step-by-step explanation:
The cost management subsystem that is designed to provide accurate and timely feedback concerning the performance of managers and others relative to their planning and control of activities is known as the c. cost accounting information system. This system is essential in tracking costs associated with specific processes or departments within a company, helping businesses to make strategic financial decisions. By analyzing cost information, managers can identify areas of inefficiency, evaluate the profitability of projects, and set future budgets with greater accuracy.