What document does the AOC serve as for merchants and service providers?

The Attestation of Compliance (AOC) is a critical document used in the context of the Payment Card Industry Data Security Standard (PCI DSS). It serves as formal documentation that a merchant or service provider has undergone an assessment to determine their compliance with the PCI DSS requirements. The AOC summarizes the assessment results and shows that the entity has met the defined security standards for protecting cardholder data.

By providing this attestation, merchants and service providers confirm their compliance status to banks, payment brands, and other stakeholders, establishing trust in their ability to securely handle payment card information. The AOC also serves as a key part of the PCI DSS compliance validation process.

This is why the answer indicating the AOC as a form that attests to PCI DSS assessment results is the correct choice. Other options do not accurately reflect the purpose of the AOC; for example, it is not a data breach signifier, nor is it a certification related to information security training or a general regulatory compliance report. Instead, it has a specific focus on the outcomes of PCI DSS assessments, which is pivotal for organizations handling credit card transactions.