A.

Transaction.Documents(0).URL

This is just the living document as it goes through its life-cycle. It's read-only and if no one has signed it - there would be no signatures on the document but if someone has signed it, they would see the signatures. It's useful as a "please view the document before signing" type of link or as a "all the signing is complete - please download the signed document for your records" type of link as well.