Which of the following is NOT a benefit of using open-source operating systems?

Using open-source operating systems offers numerous advantages, notably the ability to modify source code, free access and distribution, and, in many cases, regular updates that community contributors provide. However, one aspect that is not universally guaranteed with open-source operating systems is the consistent availability of updates from official sources.

The correct choice highlights that while many open-source systems benefit from community-driven development that can lead to regular updates, they don't always come from an official or centralized source. This can result in varying levels of update frequency and support, depending on the project's popularity and the community’s engagement. In some instances, projects may become inactive, leading to infrequent updates or even abandonment.

In contrast, the ability to modify source code allows users to tailor the software to their specific needs, and free access and distribution mean that anyone can use or share the system without financial barriers. Thus, while there can be regular updates from active projects, the potential lack of developer support differentiates open-source systems from more commercial offerings where official support is often a guaranteed aspect.