What type of transactions primarily use AVS?

The correct choice is focused on card-not-present transactions as the primary use case for Address Verification Service (AVS). AVS is a security feature used during online or over-the-phone purchases, where the cardholder is not physically present with the card. It functions by validating the billing address submitted by the customer against the address on file with the card issuer, helping to mitigate fraud risks associated with these types of transactions.

In contrast, in-person credit card transactions, cash transactions, and in-store debit card transactions do not typically require AVS because the physical presence of the card allows for alternative verification methods, such as signature checks or PIN entry. AVS is specifically beneficial in scenarios where the merchant cannot directly verify the identity of the cardholder. Thus, the emphasis on card-not-present transactions makes it clear why that answer is the most appropriate.