5. Which of the following additional facts, if established by the son, would best support his chance of obtaining rescission of the sale to the trainer?

B is correct. A person's nondisclosure of fact may be tantamount to a misrepresentation of fact sufficient to allow rescission of a contract where the person knows that disclosure of the fact would correct the other party's mistake with respect to a basic assumption of the contract, and where nondisclosure amounts to a failure to act in good faith. The fact that the horse earned $400,000 for the trainer soon after the sale (over 250 times the contract price) suggests that nondisclosure of the horse's true abilities related to a basic assumption of the contract relating to the horse's worth. If the son can establish that the trainer was aware that the horse was capable of running a race in record-setting time and that the son was ignorant of this fact, then the son has a plausible argument for rescission on grounds of nondisclosure.

A is incorrect. The son's ignorance of the horse trainer's expertise would not be sufficient to establish a basis to cancel the contract.

C are incorrect. The son's inexperience with evaluating horses alone would not be enough evidence to argue for recission.

D is incorrect. The son's anger is irrelevant to the enforceability of the contract for the horse's sale.