User interface:

The interaction between the user and the computer is provided by a facility in the operating system (OS) known as user interface. It is an important function of the OS.

There are three types of user interface, they are,

• • Graphical User Interface (GUI)
• • Menu-driven user interfaces
• • Command-line user interfaces

GUI (Graphical User Interface):

• • It is the most popular user interface design in use, which uses graphics and mouse click events to make the programs easier to use for the users.
• • Desktop is the screen image that helps the user to work in the computer in a user-friendly environment.

Menu-driven user interfaces:

• • The users need not memorize the keywords and commands that are used in the computer in menu-driven user interfaces.
• • It is operated using text-based file menus in the screen instead of using commands.
• • All the options are displayed on-screen at a given point of time; the user can select an option using the arrow keys and press enter in the keyboard.
• • Nowadays, the operating systems use both menu-driven and graphical user interfaces.

Command-line user interfaces:

• • Commands are used to instruct the operating system to perform the required operations.
• • The commands are needed to be memorized by the user, so it is not popular with the users.

Explanation for incorrect options:

CPU (Central Processing Unit) is a part of a computer that acts as the brain of the computer.

Hence, option “A” is wrong.

Control system is used to manage the external devices that are connected to the system.

Hence, option “C” is wrong.

Interactivity systems are used in managing the batch process or background process that is executed behind the user without any action being performed.

Hence, option “D” is wrong.