What is written in a program as comments?

• A. External documentation
• B. Secondary documentation
• C. Primary documentation
• D. Internal documentation

Answer: (D)

Comments written inside a program are internal documentation. They’re notes by the programmer that explain what the code does, why a certain approach was taken, or how to reuse and modify it. These comments live in the source file and are ignored by the compiler or interpreter at runtime, so they don’t change how the program runs. External documentation resides outside the codebase—like READMEs or API guides—and is intended for users or developers who aren’t reading the source directly.