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:

Central Processing Unit:

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

Hence, the option “A” is wrong.

Control System:

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

Hence, option “C” is wrong.

Interactivity System:

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

Hence, the option “D” is wrong.