Ralph enters into a contract with skye to buy her land based on her assertion that the land is open to development. after the sale, ralph learns that only a small section of the land can be built on—a local law prohibits construction on the rest of the property. ralph can: . avoid the contract due to a mutual mistake. b. not avoid the contract because persons are assumed to know the law. c. avoid the contract due to a mistake in value. d. avoid the contract due to fraud.