正解:C
A single point of failure is a component or system that, if it fails, will cause the entire system to stop functioning. In virtual environments, the hypervisor is the software layer that enables multiple virtual machines to run on a single physical host. If the hypervisor is compromised, corrupted, or unavailable, all the virtual machines running on that host will be affected. This can result in data loss, downtime, or security breaches.
References
ISACA CISA Review Manual, 27th Edition, page 254
Virtualization: What are the security risks?
What Is a Hypervisor? (Definition, Types, Risks)