Question 70

OSX is considered closed source.

OSX is a proprietary operating system developed by Apple, and its source code is not publicly available, making it a closed source system.

A) Ubuntu

Ubuntu is an open-source operating system based on Debian. Its source code is available for anyone to view, modify, and distribute, which categorizes it as open source rather than closed source.

B) Android

Although Android is based on the Linux kernel, it includes both open-source and proprietary components. While many aspects of Android are open source, the operating system as a whole includes closed-source elements, but it is still primarily considered open source.

C) CentOS

CentOS is an open-source operating system that is derived from the sources of Red Hat Enterprise Linux (RHEL). Its source code is publicly available, allowing for community support and contributions, thus it is not closed source.

D) OSX

OSX, developed by Apple, is a closed source operating system, with its source code not available to the public. This proprietary nature restricts modifications and distribution, solidifying its classification as closed source.

Conclusion

OSX stands out as the only truly closed source operating system among the options provided, as it does not allow public access to its source code. In contrast, Ubuntu, Android, and CentOS are all open source or incorporate significant open-source components, failing to meet the criteria for closed source classification.