What is the main function of the VMware Tools balloon driver?

The balloon driver, part of VMware Tools, plays a crucial role in enhancing a virtual machine's memory management. Its primary function is to facilitate memory reclamation when the host is under memory pressure. When a host system is running low on memory resources, the balloon driver "inflates" by allocating memory from the VM to the host. This allows the hypervisor to reclaim memory that can be redistributed to other VMs that need it. By doing so, the balloon driver optimizes the overall memory management of the virtualized environment, ensuring that resources are efficiently utilized.

The other options focus on different aspects of VM performance that are not directly related to memory management. High-resolution displays, improved network performance, and inter-VM communication, while important, do not pertain to the specific role of the balloon driver in managing memory within the VMware environment. Therefore, the focus on memory management is what makes the selected answer the most accurate in relation to the function of the VMware Tools balloon driver.