With respect to MS-DOS architecture, which statement correctly describes external DOS commands compared to internal commands?

Introduction / Context:
DOS distinguishes internal commands (built into the shell, typically COMMAND.COM) from external commands (standalone .COM/.EXE utilities stored on disk). Recognizing this difference explains why some commands work even if the PATH is altered or media are missing, while others fail until their files are located.

Given Data / Assumptions:

• Internal commands load with the command interpreter.
• External commands are separate executables (for example, XCOPY.EXE, FORMAT.COM).
• Execution depends on the file being found via PATH or explicit path.

Concept / Approach:
Because external commands are not part of COMMAND.COM, they remain on disk and are loaded into RAM only when invoked. If the executable is unavailable or not on the PATH, the command will not run. Internal commands, by contrast, are always available after boot because they are resident within the shell.

Step-by-Step Solution:

Verification / Alternative check:
Remove or rename XCOPY.EXE and note that the XCOPY command fails, proving its external nature; internal commands like DIR continue to work.

Why Other Options Are Wrong:

• Reside in RAM until called: Backwards; they are loaded only when called.
• Must use /e: No universal /e requirement.
• Only from batch files: They can run interactively or in batch.

Common Pitfalls:
Confusing DIR (internal) with external utilities and misconfiguring PATH so external commands are not found.

Final Answer:
External commands are stored on disk separately from COMMAND.COM