Which of the following is NOT a method to install PTA?

The installation of CyberArk's Privileged Threat Analytics (PTA) includes various methods to implement and set up the system. Among the provided options, the method that is NOT an actual method to install PTA is the virtual environment setup.

PTA can be installed by importing a disk image, which typically refers to deploying an application using pre-configured virtual machine images or similar methods. Additionally, installing PTA as software implies that it can be directly installed on existing operating systems or as part of an application stack. These methods are directly associated with the standard installation process of PTA.

In contrast, the idea of a "virtual environment setup" as a standalone method is less clear in context. While PTA can indeed be implemented within a virtualized environment, it does not represent a distinct or valid installation method on its own. Therefore, this option does not fit within the recognized methodologies for PTA installation, making it the correct answer in identifying an invalid installation approach.