The correct answer is:

(D) All of these

Explanation:

• (A): LibreOffice uses the Open Document Format (ODF) as its native file format, which is an open standard for office documents.
• (B): LibreOffice is freely available, fully-featured, and open source, making it a powerful alternative to other office suites.
• (C): LibreOffice can open and save documents in many different formats, including Microsoft Office formats (e.g., DOCX, XLSX, PPTX) and others.

So, all of the statements are correct.