Paul goes to a bar, has seven shots of whiskey, and then goes to an electronics store and buys a $2,500 stereo system. If he later wants to avoid the contract based on his intoxication when he made the purchase, he will need to prove that:

a. a reasonable person would have known that he was intoxicated.
b. his capacity to act would be classified as "legally unstable."
c. he lacked the mental capacity to enter into the contract.
d. the store clerk knew he was intoxicated.