Which of the following is not an operating system?

A. Windows
B. Linux
C. None of these
D. Oracle

🧠 Explanation:

Oracle is not an operating system, unlike Windows, Linux, or macOS. It’s a database management system used for storing and retrieving data. For tech students or IT professionals, distinguishing between operating systems and software like Oracle is crucial for understanding computer systems, database management, and their applications in business or technology, ensuring clarity in tech-related studies or careers.