DOS File Types and Extensions In MS-DOS, which filename extension specifically identifies batch command files that the command interpreter executes line by line?

Introduction / Context:
DOS uses filename extensions to distinguish how a file should be handled. Executable programs and batch scripts each have conventional extensions that determine the load and execution method used by COMMAND.COM.

Given Data / Assumptions:

• Standard DOS command interpreter: COMMAND.COM.
• Common executable-related extensions: COM, EXE, and BAT.
• System configuration files such as CONFIG.SYS use the SYS extension but are not executed as programs.

Concept / Approach:
Batch command files are plain text scripts processed by the command interpreter. DOS identifies these by the .BAT extension and executes their commands sequentially. In contrast, .COM and .EXE are binary executables loaded directly into memory and executed by DOS.

Step-by-Step Solution:
Recognize that batch files are script-like and editable in a text editor.COMMAND.COM searches for executables in the order COM → EXE → BAT unless configured otherwise.Files ending in .BAT are treated as batch scripts and executed line by line.

Verification / Alternative check:
Create TEST.BAT with a few echo commands and run TEST; DOS will execute the lines, demonstrating batch behavior. Rename it to TEST.COM or TEST.EXE to see the difference; it will not execute as a binary program.

Why Other Options Are Wrong:
COM and EXE (Options A and C) denote compiled binaries, not command scripts.SYS (Option D) is a system or driver file type and not a batch command file.

Common Pitfalls:

• Assuming .COM contains commands; it actually indicates a compact binary format.
• Misunderstanding search order and expecting .BAT to run before .COM or .EXE.

Final Answer:
BAT