Imagine that your teacher was in Cliff's Leather department store in Lafayette and he saw a briefcase with a price tag of $52. I handed the cashier a $100 bill and said, "I accept. We have a deal." The cashier then noticed the tag and tells me that an error had been made and the price is $352. Result:
a) The customer already accepted the offer.
b) The price tag was a firm offer.
c) This mistake is no defense for the store and they have to sell the briefcase $52.
d) No contract was formed because the customer's offer was refused.