Final answer:
Supporting activities in the value chain, such as accounting, facilitate and enhance the efficiency of primary activities. Accounting tracks financials and aids in strategy, distinct from the direct creation and sale process of primary activities like marketing and production.
Step-by-step explanation:
The supporting activities in a value chain represent the essential functions that assist the primary activities in providing value to a product or service. Unlike primary activities, which include the direct creation of goods and services (such as production, marketing, and sales), supporting activities are the background processes that maintain and enhance the effectiveness and efficiency of these direct actions. Therefore, among the options provided, the correct answer is A. Accounting. Accounting provides critical support by tracking financial transactions, analyzing economic performance, and ensuring regulatory compliance, which underpins the strategic decision-making process. Marketing and sales, although crucial, are classified as primary activities associated with the outward flow of the product or service, while production is the actual creation of the product.