Which of the following describes an appropriate ethical boundary for a private investigator when interacting with a client?

1. Accepting gifts or favours from the client if they are small and won't influence the investigation.
2. Providing legal advice to the client based on the investigation's findings.
3. Maintaining a professional distance and avoiding personal relationships or financial dealings unrelated to the investigation.
4. Becoming a personal confidante to the client to build trust and gather more information.