Which of the following operating systems is most commonly used in embedded systems?

Linux is the most commonly used operating system in embedded systems because it is open source, free, customizable, and supports a wide range of architectures and devices. Linux also offers many advantages for embedded development, such as real-time capabilities, modularity, security, scalability, and reliability. Linux can run on embedded systems with limited resources, such as memory, storage, or power, and can be tailored to the specific needs of the application. Linux also has a large and active community of developers and users who contribute to its improvement and innovation. Some examples of embedded systems that use Linux are smart TVs, routers, drones, robots, smart watches, and IoT devices