Which of the following would BEST help a HCISPP determine if a third party has met an external attestation for information security or privacy?

ISO certifications (e.g., ISO/IEC 27001) and SSAE No. 16 (now SSAE 18) SOC reports are formal, independent third-party attestations that verify an organization has implemented and maintains specific information security or privacy controls. These are recognized industry standards specifically designed to communicate audit results about a vendor's control environment to relying parties.

The length of time a vendor has been in business indicates market longevity but provides no evidence that the vendor meets any specific security or privacy control requirements.

Financial soundness reflects economic stability but has no direct correlation to whether a vendor has implemented adequate information security or privacy controls.

Past performance reviews are informal, retrospective assessments that lack the independent audit rigor required to constitute an external attestation of security or privacy compliance.