Who should the Scrum Master work with to determine if artifacts are completely transparent?

Answer:

Product Owner, Development Team, and other involved parties

Explanation:

In order to confirm that the events and artifacts are transparent, The Scrum Master must work in close association with the Product Owner, Development Team, and other involved parties. It is also the responsibility of the The Scrum Master to take appropriate steps if any discrepancies with regards to the process is found out.