The Parol Evidence Rule Provides What

The parol evidence rule provides what?

A) That a signed, written agreement is presumed to be the only evidence of a contract to the exclusion of other documents
B) That parties may agree that their entire agreement is to be found in a single signed written document, therefore excluding any other sources of the agreement
C) That parties to a contract can exclude liability for misrepresentation
D) That parties to a contract cannot amend it later by any means