Ada, a security professional, performed a security audit on a newly developed application to identify its weak points. Ada tested the application in an isolated virtual environment to protect the production environment from being affected by the system. Identify the technique used by Ada to test the application in the above scenario.

$*$ Application whitelisting$/$blacklisting

$*$ Application sandboxing

$*$ Application patch management

$*$ Application$-$level firewall $($WAF$)$ deployment