Which of the following project management documents is used to record challenges, problems, realized risks, and opportunities?

Information about situations that have occurred within the project, such as recording challenges, problems, realized risks and opportunities, and other relevant information for future reference, is documented in the lessons learned register. The lessons learned register is created as part of the Manage Project Knowledge process. While the term 'project documents' is technically accurate, 'lessons learned register' provides a more specific description.