Even Though Dalbert Knew Rahim Had Consumed Copious Amounts of Alcohol

Even though Dalbert knew Rahim had consumed copious amounts of alcohol during the afternoon,both signed a contract written on a napkin whereby Rahim agreed to buy Dalbert's old car for top dollar.Upon regaining his legal capacity,should Rahim opt to repudiate the contract on the basis of an improvident agreement,how must he proceed to void the contract?

A) He must claim relief due to effects of duress.
B) He must claim relief due to economic duress.
C) He must claim relief due to undue influence.
D) He must claim relief due to unconscionability.