A contract contains a provision that states it will be effective for a "year." The plaintiff in a lawsuit claims that a "year" is obviously 12 months. The defendant claims that the contract meant a 10-month school year. Parol evidence: Group of answer choices cannot be used to explain the term, because the plain meaning of a "year" is 12 months. cannot be used, because the contract contains an express term that could have been changed by the parties prior to the contract's execution. cannot be used to explain the term, because it is an integrated document. can be used to clarify the parties' intent because in this contract the term "year" is ambiguous