Final answer:
The most flexible technologies to test new security controls before deploying them are virtualization and sandboxing, as they allow for isolated and controlled testing environments.
Step-by-step explanation:
To test new security controls before deploying them, technologies that offer virtualization and sandboxing provide the most flexibility. Virtualization allows you to create simulated environments, such as virtual machines, where you can deploy and test security updates without affecting the actual production environment. On the other hand, sandboxing creates a contained, controlled, and isolated space on the system where you can execute and test new software or security controls without risking the stability or security of the host system. These technologies are crucial for both individuals and organizations to increase security measures like two-factor authentication, enforcing stronger passwords, and providing education to avoid getting scammed, thereby strengthening protections on websites and systems.