Which of the following is a containers program for virtualization?

Docker is a leading containerization program that focuses on virtualization at the application level rather than the hardware level. It utilizes a technology called OS-level virtualization, which enables multiple isolated applications or containers to run on a single operating system kernel. This approach is efficient because it allows for faster start-up times, reduced resource consumption, and easier management of applications compared to traditional virtual machines that require a full guest operating system.

In contrast to Docker, the other options are primarily traditional virtualization solutions that provide virtual machines (VMs) rather than containers. These solutions create separate virtual environments that emulate entire operating systems, which is a more resource-intensive process. Therefore, Docker’s specialized focus on containers aligns it with lightweight and efficient application deployment and scalability, whereas the other programs are geared toward full virtualization.