When a legacy application is running on multiple physical servers, and the organization wants to maintain it until retirement, the best CompTIA-aligned solution is virtualization. Virtualization allows the engineer to convert existing physical servers into virtual machines (VMs), a process known as P2V (Physical-to-Virtual) migration. This reduces hardware footprint, simplifies management, and isolates the application within a controlled environment. CompTIA A+ emphasizes virtualization for legacy support because it eliminates dependence on aging physical hardware while preserving application functionality exactly as before.
Virtual machines also provide snapshots, backups, failover capabilities, and easier resource allocation, making them more reliable than maintaining old hardware. A SAN (A) provides storage, not application hosting. FaaS (B) is a serverless model inappropriate for legacy applications that require full OS environments. A configuration management platform (D) manages software deployments and settings but does not replace or consolidate physical servers.
Thus, virtualization is the most suitable and industry-standard method for sustaining legacy applications.