"Access Authentication" is more of an added layer of security then it is a guarantee that the document in the envelope was read. Basically with additional authentication the Recipient either is sent a code or is sent a code via phone or text to enter at the time they open the envelope thus ensuring the proper Recipient opens the envelope.

What you want to use is some method to guarantee (as much as you can) that the Recipient read the term or conditions. Typically I would suggest adding a clause in the document stating that the "Recipient has read and agrees to the terms and conditions of the above document" then set either a Signature or an Initials for that Recipient next to that statement which make the Recipient type set for that Recipient as "Needs to Sign". Just a "Receives a Copy " recipient type is a non-action recipient type meaning they just get a notification and attachment with the document but it does not ensure they read that attachment or document. You could also use a "Needs to View" Recipient Type which does not require any filling of fields or Signature but requires the Recipient to open the document. Again this does not ensure they "read" the document just opened it.