Software re-engineering is concerned with:

• A. Re-constructing the original source code from the existing machine (low - level) code program and modifying it to make it more user - friendly.
• B. Scrapping the source code of a software and re-writing it entirely from scratch.
• C. Re-organising and modifying existing software systems to make them more maintainable.
• D. Translating source code of an existing software to a new machine (low - level) language.