The parol evidence rule may prohibit modifying a fully integrated contract, but it permits extrinsic evidence to interpret ambiguous terms.

• A. The parol evidence rule applies only to oral contracts.
• B. The parol evidence rule prohibits extrinsic evidence to modify a fully integrated contract, with no exceptions.
• C. The parol evidence rule applies only to contracts for sale of goods.
• D. The parol evidence rule prohibits extrinsic evidence to modify a fully integrated contract, but allows extrinsic evidence to interpret ambiguous terms.

Answer: (D)