During an iteration of a project, a planned activity becomes more complex.

 A cross-functional team is a group of people with different skills and expertise who work together to achieve a common goal. A cross-functional team is beneficial for agile projects, as it enables the team to deliver value faster, collaborate better, and adapt to changing requirements and customer feedback. When a planned activity becomes more complex, the best approach is to have the cross-functional team work together to complete the activity, as this allows the team to leverage their diverse skills and knowledge, share ideas and solutions, and overcome challenges and risks. The team can also communicate and coordinate more effectively, and ensure that the quality and scope of the activity are met. This is part of the Execute Project Work process, which aims to perform the activities that produce the project deliverables. The other options are not the best choices because they do not utilize the full potential and capacity of the cross-functional team. The team facilitator gets support from external team members (option A) may introduce more complexity and dependency, as the external team members may not be familiar with the project context, objectives, and processes. The team members bring in a specialist to help them (option B) may be helpful, but it may also create a bottleneck and dependency, as the specialist may not be available or accessible when needed. The product owner moves it to the product backlog (option C) may delay the delivery and value of the activity, as the product backlog is a prioritized list of features and requirements that the team will work on in future iterations. It may also create dissatisfaction and frustration among the team and the customer. References:

Project Management Professional (PMP) Reference Materials:

A Guide to the Project Management Body of Knowledge (PMBOK Guide), Sixth Edition, Chapter 4: Project Integration Management, pp. 71-123

Agile Certified Practitioner | PMI

Professional in Business Analysis (PBA) Reference Materials:

Business Analysis for Practitioners: A Practice Guide, Chapter 5: Requirements Elicitation and Analysis, pp. 79-80

The Benefits of Cross-Functional Teams on Your Projects