What elements are included in the Mac OS X/macOS kernel?

The Mac OS X/macOS kernel is built on a foundation that includes the Mach kernel and the XNU kernel, which stands for "X is Not Unix." The Mach kernel is responsible for tasks like managing memory, scheduling processes, and handling inter-process communication, while the XNU kernel combines elements from both Mach and BSD (Berkeley Software Distribution) Unix. This integration allows macOS to offer a robust performance and a familiar Unix-like environment, while also providing user-space abstractions that support the various graphical and development frameworks such as Cocoa and Carbon.

The other options do not accurately represent the kernel components of macOS. ARM architecture refers to a type of processor design, unrelated to the specific kernels used in macOS, while the Linux kernel is not a part of macOS; in fact, macOS is distinct from Linux despite both systems being Unix-like. The mention of the Windows NT kernel is also misplaced, as it pertains to a completely different operating system ecosystem. Cocoa and Carbon are application frameworks used in macOS development rather than components of the kernel itself.