Which ability describes a security feature in virtualization?

The ability that describes a security feature in virtualization is isolating the operating system when running multiple concurrent virtual machines (VMs). This isolation is a fundamental aspect of virtualization technology that enhances security and stability in a multi-tenant environment. With virtualization, each VM is containerized so that it operates independently of others. This means that if one VM experiences a security breach or malfunction, it does not directly affect the other VMs running on the same host.

This separation helps to protect sensitive data and applications within one VM from being accessed or compromised by another VM, thereby minimizing the risk of security vulnerabilities spreading throughout the entire system. Additionally, this isolation allows for better resource management and provides a controlled environment for running untrusted applications without risking the host operating system.

In comparison, while other options relate to important security practices, they do not specifically pertain to the inherent features that virtualization technology provides. For example, encryption of data, network segmentation, and multi-factor authentication are all significant security concepts, but they do not represent the core security function that is achieved through the isolation of operating systems in a virtualized environment.