A company will retire a legacy application in one year but wants to decommission the...

CompTIA A+ emphasizes virtualization as an ideal solution during system phase-out or transition periods. The correct approach here is a P2V (physical-to-virtual) conversion and hosting the server in an Infrastructure as a Service (IaaS) environment. This removes the need for physical hardware while still keeping the application operational for its final year. IaaS provides full control over OS and applications, making it suitable for legacy systems that cannot be rewritten.

Colocation (Option A) still requires physical hardware. PaaS (Option C) is inappropriate because PaaS requires rewriting or replatforming the application. Shutting down the server after a backup (Option D) makes the application immediately unusable.

Thus, the best method is to convert to a virtual machine and host it on IaaS.