Which Windows feature provides virtualization capabilities allowing multiple operating systems to run on one machine?

Correct answer: Hyper-V

Option D is correct because Hyper-V is Microsoft's native hypervisor technology built into Windows (Pro, Enterprise, and Education editions) that enables hardware virtualization, allowing multiple guest operating systems to run concurrently on a single physical machine. Option A is wrong because a Virtual Private Network (VPN) is a secure network tunneling technology for private communication over public networks, not a virtualization platform. Option B is wrong because Virtual Memory is a memory management technique that uses disk space to extend apparent RAM, not a mechanism for running multiple operating systems. Option C is wrong because Remote Desktop is a protocol and feature for accessing a Windows desktop remotely over a network, which has nothing to do with running multiple OS instances.