The first step in addressing an underperforming team member is to understand the root cause of the underperformance. This can be achieved by having a private discussion with the team member to understand their perspective and challenges. This approach promotes open communication and trust, and it allows the project manager to work collaboratively with the team member to find a solution. The other options may not address the root cause of the problem and could potentially lead to further issues down the line. References:
PMBOK Guide, 6th Edition, Section 9.5.2.1: Team Performance Assessments