What is the primary function of an acquiring processor?

The primary function of an acquiring processor is to provide operational services for credit card transactions. This includes a range of responsibilities such as processing payment authorizations, facilitating communication between merchants and card networks, and ensuring that transactions are settled correctly and efficiently. Acquiring processors play a critical role in the payment ecosystem by acting as intermediaries that help businesses accept electronic payments securely and accurately. Their expertise and infrastructure enable merchants to process card transactions seamlessly, manage transaction data, and ultimately facilitate sales.

The other options, while relevant in the broader context of the payment industry, do not accurately describe the core responsibilities of an acquiring processor. Issuing credit cards and managing relationships with cardholders pertain more to the role of issuing banks, while determining merchant eligibility is typically the responsibility of acquiring banks or organizations. Hence, option C stands out as the most accurate reflection of what an acquiring processor does.