The correct answer is C - Ask management to ensure that the resource is available to only one project at a time.
Agile promotes dedicated, stable teams over multitasking. Task-switching reduces productivity and leads to context-switching overhead. If a key resource is overburdened and switching between multiple projects, the best solution is to secure focused commitment by escalating to management for support.
PMI Agile Practice Guide:
"Agile teams should be dedicated and work on one project at a time. Splitting attention across multiple efforts reduces velocity and quality due to context switching." (PMI Agile Practice Guide, Section 6.1 - Team Composition) Mike Griffiths highlights:
"Effective agile teams are stable, long-lived, and dedicated. Shared resources create bottlenecks, undermine predictability, and impair team dynamics." (PMI-ACP Exam Prep, Chapter 4 - Team Performance) Incorrect options:
* A may solve bandwidth issues but not focus or ownership.
* B addresses symptoms, not the core issue of divided focus.
* D tolerates a harmful practice that contradicts agile team stability.