In PCI DSS, which data should typically be masked in reports?

In the context of PCI DSS, masked data typically involves presenting only a limited portion of sensitive information to protect it while still allowing for useful reporting. The correct response indicates that the full card number should be masked, such that only the last four digits are visible. This practice maintains a level of confidentiality for the majority of the card number, which is crucial for safeguarding against unauthorized access and potential fraud.

PCI DSS guidelines specifically emphasize the necessity of protecting cardholder data, which includes the full card number, often referred to as the Primary Account Number (PAN). By masking it and displaying only the last four digits, organizations can still use this data for legitimate business functions, such as transaction verification or customer service inquiries, while minimizing the risk of exposing sensitive information.

The other options present different forms of data that either do not require similar mask protection under PCI DSS guidelines or do not appropriately align with valid masking practices for reports.