During the execution of a project the project manager notices that only one team member...

 These two actions can help prevent the team from being unqualified, because they can enhance the skills and competencies of the team members who lack the technical skill needed to build the product. Encouraging working in pairs and knowledge sharing can foster collaboration and learning among the team members, and allow the team member who has the technical skill to transfer it to others through coaching, mentoring, or feedback. Facilitating a training event with an external trainer can provide a formal and structured way of teaching the team members the technical skill, and ensure that they have the necessary knowledge and practice to apply it to the project. These actions can also improve the team performance, morale, and confidence, and reduce the dependency on one team member. The other options are not effective actions to prevent the team from being unqualified, because they may not address the skill gap or the project requirements, or they may create more problems or risks. Excluding the activities from the roadmap may not be possible or desirable, and it may affect the scope, quality, or benefits of the project. Teaching the entire team the new skill may not be feasible or efficient, and it may overload the project manager or the team member who has the skill. Increasing the time estimates on the activities that require such abilities may not be realistic or accurate, and it may delay the project schedule or increase the project cost. References: Project Resource Management - PMBOK Guide, What Actions Can the Project Manager Take to Ensure Effective Teamwork?