According to the PMBOK Guide, the project manager is responsible for managing the project team and resolving any conflicts that may arise among team members. The project manager should use appropriate conflict resolution techniques, such as problem-solving, compromising, or collaborating, to identify the root causes of the issues and guide the team members toward a mutually acceptable solution. Removing one of the team members, warning them about their behavior, or training them on communication techniques and interpersonal behavior are not effective ways of handling this situation, as they do not address the underlying problems or foster a positive team environment. References: PMBOK Guide, 7th edition, page 223-224; PMBOK Guide, 6th edition, page 349-350.