Final answer:
The 'Manage Stakeholder Expectations' process is part of the Monitoring and Controlling process group in project management, aiming to keep stakeholders informed and engaged.
Step-by-step explanation:
The process group that 'Manage Stakeholder Expectations' belongs to within project management is the Monitoring and Controlling process group. This activity is crucial for project success because it involves communicating and working with stakeholders to meet their needs and address issues as they arise. Managing expectations is about keeping stakeholders engaged and informed throughout the project lifecycle, providing updates, and mitigating any concerns that may impact their perception of the project's success.