An AI auditor is reviewing evidence that an organization's AI model governance practices comply with their stated policy. Which audit evidence is MOST persuasive for demonstrating that model validation independence is maintained?

B is correct because audit evidence must be sufficient, reliable, and relevant. Signed validation reports combined with work papers showing actual independent testing performed on validators' own infrastructure provide direct evidence of independent execution. An org chart (A) shows structural independence but not operational independence. A policy document (C) is a process control, not evidence of compliance with the control. A CRO attestation (D) is management representation, which is the least reliable form of audit evidence as it is based on the auditee's own assertion.