Which of the following alternative technologies allows a computer to run multiple operating systems without partitioning the hard drive?

Web applications run in a web browser and are not an alternative technology for running multiple operating systems on a local machine.

Dual boot is a method where multiple operating systems are installed on separate partitions of a single hard drive, and the user chooses which OS to boot into at startup, which explicitly involves partitioning.

Telepresence is a technology that allows a person to feel as if they are present at a remote location, and it has no relation to running multiple operating systems on a computer.

Virtualization allows a hypervisor to create and run multiple virtual machines (VMs) on a single physical host, with each VM capable of running its own operating system (guest OS). This method does not require partitioning the physical hard drive for each OS, as the VMs store their operating systems and data in virtual disk files.