The stakeholder register is a key input for managing communications. In Agile, frequent communication and stakeholder inclusion are vital. If there's a failure due to incorrect contact data, the Scrum Master should proactively review and verify the full stakeholder register to ensure it's accurate and complete, preventing recurrence. According to the PMBOK Guide - Seventh Edition (Stakeholder and Communication Performance Domains), it is the responsibility of the project team to maintain accurate stakeholder information. This promotes engagement, transparency, and effective decision-making. Option A places undue burden on the product owner and is inefficient. Option B shifts responsibility to the stakeholder. Option C demonstrates poor accountability. References: PMBOK Guide - Seventh Edition, Stakeholder Performance Domain Agile Practice Guide, Chapter 4 - Stakeholder Engagement ##############################################