The question asks us to identify which option is not an example of system software. Let us analyze each option:
- (A) Operating System:
An operating system (e.g., Windows, macOS, Linux) is a core component of system software. It manages hardware resources and provides a platform for running application software. Hence, this is system software.
- (B) Debugger:
A debugger is a tool used to find and fix errors in programs. While it is often part of development environments, debuggers are typically classified as system software because they help manage and control the execution of programs. Hence, this is system software.
- (C) Software Driver:
Software drivers are programs that allow the operating system to communicate with hardware devices (e.g., printers, graphics cards). These are essential components of system software. Hence, this is system software.
- (D) Adobe Photoshop:
Adobe Photoshop is a graphic design software used for creating and editing images. It is a type of application software, not system software. Hence, this is not system software.
From the analysis above, the correct answer is:
\[
\boxed{\text{(D) Adobe Photoshop}}
\]