A highly skilled team resource received a job offer and is leaving the project soon...

According to the PMBOK Guide, 6th edition, page 341, cross-training and mentoring are two of the techniques for developing the project team. Cross-training allows team members to acquire new skills and knowledge from other team members, while mentoring provides guidance and support from experienced team members. These techniques can help the new team member to integrate into the project team, learn the project processes and procedures, and improve their performance and productivity. They can also reduce the impact of the loss of the highly skilled team resource and maintain the project performance. References: PMBOK Guide, 6th edition, page 341; Free PMP Practice Exam Questions - 120 Sample Test Questions