The Parol Evidence Rule

The parol evidence rule:

A) states that any spoken or written words that are in conflict with what the written contract states should be introduced as evidence in a court of law.
B) refers to supplementary evidence or conditions that a party wants to be added to an existing written contract.
C) specifies that certain kinds of agreements must be in writing to be enforceable.
D) does not prohibit a person from legally entering into oral contracts for certain kinds of agreements.