The correct answer is UNIX.UNIX has the exclusive feature SHELL.A Unix Shell is a command-line interpreter or shell that provides a command-line user interface for Unix-like operating systems.The shell is both an interactive command language and a scripting language and is used by the operating system to control the execution of the system using shell scripts.Users typically interact with a Unix shell using a terminal emulator;However, direct operation via serial hardware connections or Secure Shell is common for server systems.All Unix shells provide filename wildcarding, piping, here documents, command substitution, variables, and control structures for condition-testing and iteration.Additional Information A disk operating system (DOS) is a computer operating system that can use a disk storage device, such as a floppy disk, hard disk drive, or optical disc.A disk operating system must provide a file system for organizing, reading, and writing files on the storage disk.Application software:This software is used by the user to perform a specific taskIt is also known as the end-user programApplication software programs are developed to assist you with a particular process that may be related to creativity, productivity, or better communication.It is non-essential software.Application software runs as and when the user requests it.Some of the examples of application software are, google chrome, internet explorer, VLC media, etc.System softwareIt is a type of computer program that is designed to run a computers hardware and application programs.If we think of the computer system as a layered model, the system software is the interface between the hardware and user applications.The operating system (OS) is the best-known example of system software. The OS manages all the other programs on a computer.