What type of virtual disk is defined by selecting a size that does not change?

The correct choice is thick provisioning. In the context of virtual disks, thick provisioning refers to allocating a fixed amount of storage space at the time the virtual disk is created. This means that the size you select does not change over time and the full amount of space is reserved regardless of how much data is actually being stored on the disk.

When thick provisioning is used, the virtual disk is not able to dynamically resize based on data consumption. This can be beneficial in scenarios where consistent performance is required, as the dedicated space ensures that the virtual machine will not encounter performance degradation due to overprovisioning.

In contrast, thin provisioning allows for a disk to initially take only what it needs and expand as additional storage is required, while dynamic and static provisioning relate to different management aspects of storage allocation but do not capture the concept of a fixed size in the same manner as thick provisioning.