Which of the following statements is incorrect?

a. operating systems must provide both command line as well as graphical user interfaces
b. an operating system provides an environment for the execution of programs
c. an operating system manages system resources
d. operating systems may provide both command line as well as graphical user interfaces
e. operating systems must provide both protection and security

Option A and D contains same answer. Both options are incorrect

Operating systems provide both command line as well as graphical user interfaces

Explanation:

An immersive graphical component system for computer software is a graphical user GUI. A GUI is seen as more simple than a graphical unit-line interface, like MS-DOS or a Unix-like operating system shell.

In a GUI, commands like opening, deletion and moving files are executed using a window, an icon and menu. While a mainly mouse-based GuI operating system is used, a keyboard can also be used through keyboard shortcuts or arrow keys.

For example, you would move the mouse cursor to the icon of the program and double click on it to open a program on a GUI system.