Which operating system does NOT have Reduced Functionality Mode (RFM)?

Reduced Functionality Mode (RFM) is a feature that restricts the capabilities of an operating system or application when certain conditions are not met, such as activation or compliance. In this context, Windows is known for its RFM, where if a system is not properly activated, it enters a limited functionality state, allowing only certain features or capabilities.

Linux and Android do have their own versions of restricted operations, particularly in terms of user permissions and software restrictions, but they do not operate under the specific framework of RFM defined within a Windows context. macOS, however, does not employ RFM as a standard practice. Instead, it might restrict certain applications or functionalities based on user permissions or licensing agreements, but it does not have an official "Reduced Functionality Mode" like Windows.

Therefore, macOS stands out as the correct answer in that it lacks the designated RFM system that is characteristic of Windows environments, where RFM is a clearly defined response to activation or compliance issues.