Wilbur decides to sell his collection of rare stamps on Ebay. When he is filling out the information for his item, he types $40

instead of $400 in the reserve price box. Wilbur does not notice his mistake until after the auction is over and someone has purchased his stamp collection for $75. Wilbur:
a. can rescind the contract because the stamps are worth much more than $75.
b. can rescind the contract because he made a unilateral mistake.
c. can claim he was defrauded.
d. cannot rescind the contract based on his unilateral mistake.