Explanation
According to the PMBOK Guide 7th Edition, an agile project is a project that uses an adaptive, iterative, incremental, or agile approach to deliver value to the customer in a fast and flexible way. An agile project typically consists of a self-organizing and cross-functional team, which is empowered to make decisions and collaborate with each other to achieve the iteration goals. If a team member's performance is poor and affects the team's ability to meet the iteration goals, the project manager should allow the project team to discuss the problem with this team member, and to provide feedback, coaching, and support to help the team member improve their performance. This will help to foster a positive and supportive team culture, where team members can communicate openly, trust each other, and share their ideas and concerns. Discussing the issue with the team member's functional manager, informing the HR department, or speaking to the team member are not the best actions, as they do not demonstrate the project manager's respect for the team's autonomy and accountability, and they may undermine the team's cohesion and motivation. References: PMBOK Guide 7th Edition, page 19-20.