Answer:
C. Yes, since the mistake would be obvious to a reasonable person.
Step-by-step explanation:
A unilateral mistake occurs when only one party is mistaken as to the subject matter or the terms contained in the contract agreement.
The general rule involving unilateral mistakes is that, if the non-mistaken party either knew or should have known of the other party's mistake, the mistake is a “palpable unilateral mistake” which makes the contract voidable by the mistaken party.
Therefore, since Vinny's mistake would have been obvious to the other party, it could make the contract voidable and relieve the store of the liability.