A key stakeholder requests a significant feature addition during the execution phase of a predictive project. The change would add substantial business value but would impact the timeline by 8 weeks and increase the budget by 20%. The change also affects multiple other project components. What should the project manager do FIRST?

Implement the change immediately since it adds substantial business value to the project

Reject the change to protect the project baseline, timeline, and budget commitments

Conduct a comprehensive impact assessment on scope, schedule, cost, quality, risk, and component integration, then submit to change control board

Negotiate with the stakeholder to implement a reduced version of the feature that has less impact