Which stage of the operating system life cycle provides support for critical security updates after mainstream support ends?

The stage of the operating system life cycle that provides support for critical security updates after mainstream support ends is the Extended Support phase. This phase is designed to address ongoing security issues and provide important patches for vulnerabilities, ensuring that the system remains secure even though it is no longer receiving the full range of updates and new features offered during mainstream support.

During the Extended Support phase, organizations that rely on the operating system can still receive crucial security updates, making it possible to protect their systems from emerging threats. This support typically lasts for a defined period, allowing businesses to plan for migrations to newer versions while maintaining security on their existing systems.

The other stages do not offer this specific type of support after mainstream support concludes. Initial Support and Active Support generally include a wider range of updates, including functional enhancements and bug fixes, while the Maintenance Phase primarily focuses on stabilizing the product rather than providing security updates.