According to the PMBOK® Guide (Project Management Body of Knowledge), specifically within the Project Communications Management knowledge area and the Manage Communications process:

Project Records (Option A): These include correspondence, memos, meeting minutes, and other documents that describe the project. When project issues are resolved, the documentation of these resolutions becomes part of the permanent project records. According to PMI, the " Manage Communications " process results in updates to project records, which are then used to keep stakeholders informed of the project ' s status and resolved issues.

Project Reports (Option B): While project reports (like status reports or progress reports) are used to deliver information, they are a specific type of communication output. The broader category for the storage and archival of these resolved issues for stakeholder reference is project records.

Stakeholder Notifications (Option C): This is an output of the Manage Communications process that refers to the act of informing stakeholders about resolved issues, approved changes, or project status. However, the question asks where the information is updated/stored to facilitate this communication, which points to the records.

Stakeholder Register (Option D): This is a project document that contains information about project stakeholders, including their identification, assessment, and classification. It is not used to document or communicate the resolution of specific project issues.

In the PMI framework, maintaining accurate and thorough project records ensures that there is a " single source of truth " for all stakeholders regarding what issues were encountered, how they were analyzed, and how they were ultimately resolved.