Ohner and Planner signed a detailed writing in which Planner, a landscape architect, agreed to landscape and replant Ohner's residential property in accordance with a design prepared by Planner and incorporated in the writing. Ohner agreed to pay $10,000 for the work upon its completion. Ohner's spouse was not a party to the agreement, and had no ownership interest in the premises.For this question only, assume the following facts. Shortly before the agreement was signed, Ohner and Planner orally agreed that the writing would not become binding on either party unless Ohner's spouse should approve the landscaping design. If Ohner's spouse disapproves the design and Ohner refuses to allow Planner to proceed with the work, is evidence of the oral agreement admissible in Planner's action against Ohner for breach of contract?
Yes, because the oral agreement required approval by a third party.  Yes, because the evidence shows that the writing was intended to take effect only if the approval occurred  No, because the parol evidence rule bars evidence of a prior oral agreement even if the latter is consistent with the terms of a partial integration.  No, because the prior oral agreement contradicted the writing by making the parties' duties conditional.