Explanation = The project manager should have facilitated cross-functional knowledge transfer during the project to prevent the situation where a single team member's absence would jeopardize the project progress. Cross-functional knowledge transfer is a way of sharing skills, expertise, and information among team members to enhance collaboration, innovation, and performance. It also reduces the risk of knowledge loss or dependency on a single resource. Requesting robust documentation, outsourcing development, or acquiring more resources are not the best ways to prevent this situation, as they may not be feasible, cost-effective, or timely. References: PMBOK Guide 7th Edition, Chapter 7: Team Performance, Section 7.2: Enable Team Performance, Page 181 PMBOK Guide 6th Edition, Chapter 9: Resource Management, Section 9.3: Develop Team, Page 336 Agile Practice Guide, Chapter 3: Implementing Agile: Creating an Agile Environment, Section 3.4: Delivery Practices, Page 40
