Answer:
The correct answer is option d) He has saved the document only once.
Step-by-step explanation:
If you are working on a document, and have not yet saved it, its default name will be "Document".
When you want to save it, you could change the name once the document is ready.
If you save the document and it is saved with the name "Document", when you want to save it a second time, its name will automatically be "Document1", if you save it twice its name would be "Document2" and so on.
Therefore, this leads us to the conclusion that Rico has only saved the document once.