Which of the following is an application virtualization solution?

The correct answer is an application virtualization solution because Microsoft App-V is specifically designed to allow applications to run on a client device without being installed in the traditional sense. This technology streams applications directly from a server to the end user's device, allowing them to use the applications as if they were installed locally, while keeping the actual application data separate from the operating system.

In contrast, Oracle VirtualBox, Parallels Workstation, and VMware Workstation are virtualization platforms that provide full virtual machines (VMs) for running entire operating systems and their associated applications, rather than solely focusing on individual application virtualization. This distinction is crucial, as traditional virtualization solutions manage complete OS instances rather than lightweight, isolated applications that App-V handles.