Which of the following entities will ultimately approve a purchase?

The issuer is the entity that ultimately approves a purchase because it is the bank or financial institution that issued the credit or debit card being used for the transaction. When a consumer makes a payment, the transaction request is sent to the issuer to verify whether the cardholder has sufficient funds and that the card is valid. The issuer assesses the transaction for several factors, including account status and risk, and then either approves or declines the transaction based on these criteria. This is a critical step in ensuring secure and reliable financial transactions.

While other entities, such as merchants, payment processors, and acquirers, play significant roles in the payment process, they do not have the authority to approve the actual purchase. Merchants initiate the transaction and can determine whether to accept it based on their policies, payment processors facilitate the communication between the various parties, and acquirers manage merchant accounts and procedures for settling transactions, but the final approval comes from the issuer.