The correct answer is A. Cost reduction.
Cost reduction is a preventive function because it aims to identify and eliminate unnecessary costs before they occur. This can be done by analyzing costs, identifying areas where costs can be reduced, and implementing cost-saving measures.
Cost control is a reactive function because it aims to monitor and control costs that have already been incurred. This can be done by setting budgets, tracking actual costs, and taking corrective action when costs exceed budget.
A cost unit is a unit of measurement used to track costs. This can be a product, service, department, or any other unit that is relevant to the organization.
A cost center is a unit of organization that is responsible for incurring costs. This can be a department, division, or any other unit that is responsible for managing its own resources.
Cost reduction is a more proactive approach to cost management than cost control. Cost reduction aims to prevent costs from occurring in the first place, while cost control aims to manage costs that have already been incurred. Cost reduction is often more difficult than cost control, but it can be more effective in the long run.