Which of the following refers to programs running in an isolated space to run untested code and prevents the code from making permanent changes to the OS kernel and other data on the host machine?

Input validation sanitizes data entering an application to prevent injection attacks but does not create an isolated execution environment for untested code.

Application hardening reduces an application's attack surface through secure configuration and patch management but does not isolate code execution from the underlying OS.

Code signing uses cryptographic signatures to verify software authenticity and integrity but does not restrict or isolate how the code executes on the host system.

Application sandboxing creates a confined execution space where code runs with restricted access to system resources, the OS kernel, and user data. Any changes made within the sandbox are temporary and discarded when the session ends, preventing permanent damage to the host. This technique is widely used for running untrusted code, analyzing malware, and testing applications safely without risk to the underlying system.