What file format bundles all of the virtual machine configuration files into a single tar file for distribution?

The correct choice for the file format that bundles all of the virtual machine configuration files into a single tar file for distribution is the OVA format. OVA stands for Open Virtual Appliance, and it serves as a single file distribution format for a virtual appliance. The OVA file is essentially a tar archive that contains all the necessary files needed for the virtual machine, including the virtual disk images, configuration files, and metadata. This makes it incredibly convenient for sharing or deploying virtual machines, as everything is packaged together in a cohesive manner.

In contrast, the other options represent different types of virtual machine file formats. VMDK is a file format used by VMware for virtual disks but does not package configuration files. ISO files are disk image files typically used for distribution of operating system installation media, not virtual machines. VHD is a format used for virtual hard disks, primarily associated with Microsoft’s virtualization technologies, and it also does not encapsulate configuration files into a single distributable format. Thus, OVA stands out as the appropriate answer for bundling all relevant components of a virtual machine into a single file.