Answer:
Microsoft Word
Step-by-step explanation:
If you want to create a cover letter to send to potential employers, along with a resume, you should use microsoft word to create these documents. Microsoft is the most appropriate software for the documents you want to create, because it is not possible to create a cover letter let alone a resume using Twitter, and twitter is not an appropriate place for this type of document.
Similarly, Microsoft Excel and PowerPoint software are not suitable for creating the documents you want, as they would create the documents in a strange design for that type of document, which would take away all the credibility and formality that the author of the documents would need.