Comprehensive and Detailed 200 to 250 words of Explanation From Exact Extract of project-programme-and-portfolio-management of 5th Edition MSP:

The Senior Responsible Owner (SRO) is the individual ultimately accountable for the programme. One of the SRO's primary responsibilities is to ensure that the programme is governed effectively and that all necessary controls are in place to protect the organization and ensure benefit realization. Governance includes the approval of the Programme Strategy and its subsidiary plans, such as the Risk Management Approach and the Transition Plan.

In this scenario, holding a risk review before transition is a critical governance control. Because this decision was agreed with the Sponsoring Group, it becomes a formal part of the programme’s oversight framework. Option A is correct because the SRO is the person authorized to approve the "rules of the game" for the programme. While the Programme Manager (Option B) might draft the document and the Programme Office (Option D) might maintain it, the authority to approve how the programme will be controlled—especially regarding high-stakes activities like transitioning to new customer processes—rests with the SRO. The SRO must be satisfied that the risks are being managed before the business assumes the impact of the change. This ensures that the programme remains aligned with corporate risk appetite and strategic objectives.