Which of the following refers to the essential software that enables a computer's functionality?

The operating system serves as the fundamental software that manages all hardware and software components on a computer. It acts as an intermediary between users and the computer hardware, allowing users to execute commands and manage files while also controlling peripheral devices. The operating system provides essential services, such as managing memory, processing tasks, enforcing security, and facilitating user interaction through graphical interfaces or command lines.

System utilities, while important, are applications that help maintain the overall health and performance of the computer, but they do not make the system functional on their own. Application software refers to programs that perform specific tasks for users, such as word processing, web browsing, or gaming, and relies on the operating system to function. Device drivers are specialized software components that allow the operating system to communicate with hardware devices, but they are not the foundational software that enables overall functionality. Thus, the operating system is the core software that makes the computer operational and integral to performing all computing tasks.