What does a successful Mod 10 test indicate about a primary account number (PAN)?

A successful Mod 10 test, also known as the Luhn algorithm, is utilized to help verify the validity of a primary account number (PAN). When a PAN passes this check, it indicates that the number follows the correct format and checksum rules that are typical for credit or debit cards. However, it does not guarantee that the number is an active or issued card; rather, it suggests that the number could be valid.

This means that while the number adheres to the structural rules that define a valid card number, it is still possible that it could be fake, unassigned, or even issued to a card that isn't active. Thus, the outcome of the Mod 10 test points to a potential validity, but additional confirmation would be required to determine actual assignment and usability of the PAN in payment processing.

Other options imply certainty or invalidity which doesn’t align with what the Mod 10 test accomplishes, hence those do not reflect the accurate interpretation of a successful test outcome.