Which is valid extension that user creates on operating system? A. Exe B. Com C. Sys D. Bat

The correct answer is D. Bat.

A batch file is a text file that contains a series of commands to be executed by the Windows command-line interpreter, cmd.exe. Batch files are often used to automate repetitive tasks, such as launching programs, copying files, and deleting directories.

The other options are not valid extensions that a user can create on an operating system.

• Exe: An executable file is a file that contains instructions that can be executed by the computer. Executable files are typically used to launch programs.
• Com: A COM file is a type of executable file that was used in early versions of Windows. COM files are no longer supported in modern versions of Windows.
• Sys: A system file is a file that is essential to the operation of the computer. System files are typically hidden from the user and should not be modified.