Which of the following is a feature of the NX protocol?

The NX protocol is primarily known for its ability to enable remote desktop connections that are both efficient and effective, especially in conditions with limited bandwidth. One of its key features is its support for accessing virtual machines. This capability allows users to connect to virtual instances running remote desktop environments seamlessly.

This feature is advantageous because it enables users to manage and interact with virtual machines as if they were physically present at the machine, providing flexibility in managing resources and optimizing workflows. Moreover, the ability to connect to virtual machines enhances the use of the NX protocol in cloud environments and virtualized infrastructures, making it a widely adopted tool for remote access.

The other options do not accurately reflect the capabilities of the NX protocol. It is indeed available in both free and paid versions, can operate over the internet and on local networks, and is capable of supporting multi-session environments allowing multiple users to connect concurrently. These aspects highlight the versatility and robustness of the NX protocol in various usage scenarios.