Which of the following is an example of hardware in a computer system?

A hard drive is indeed an example of hardware in a computer system. Hardware refers to the physical components that make up a computer and can be touched or seen. The hard drive is a crucial storage device that holds the operating system, software applications, and data files, allowing the computer to retrieve and store information as needed.

In contrast, the other options represent software, which consists of programs and applications that run on the hardware. The operating system software coordinates the hardware and manages the resources of the computer, while an antivirus program provides security by detecting and managing threats, and a web browser allows users to navigate the internet. None of these options can be physically touched or seen as they are comprised of code and instructions processed by the hardware. This distinction between hardware and software is fundamental in understanding computer architectures and their functionalities.