Final answer:
An audit trail is represented by option (a), where a research team keeps detailed records of their process, allowing for external review and verification.
Step-by-step explanation:
The question asks which of the following represents an audit trail. The correct answer is (a), where a team of researchers keeps a detailed recollection of their research process, which involves archival research methods and allows for someone external to the team to review these materials for any problems or issues. This encompasses maintaining records such as recruitment materials, focus group guides, transcribed focus groups, and data analysis materials like a code book. Having this detailed process documented creates an audit trail, which is essential for verifying the research methodology and ensuring integrity of the data and findings.