正解:D
Answer D is the technically correct selection. Virtual machines are operating system instances decoupled from the physical server hardware. The hypervisor presents virtual CPU, memory, disk, and NIC resources so multiple VMs can run on one host. This aligns with Cisco CCNA 200-301 v1.1 because the exam blueprint requires engineers to recognize operational behaviour from configuration symptoms and topology requirements. The VM does not manage host resources itself, and the physical server can run multiple OS instances concurrently through virtualization. Treat the distractors carefully: most are real Cisco terms, but they solve a different problem or operate at a different layer. The selected answer is the one that would be used by an engineer on the device or in the design to produce the outcome stated in the question.