Catherine and Jacob Have a Written Contract to Buy and Sell

Multiple Choice

Catherine and Jacob have a written contract to buy and sell "100 cases of widgets." The 100 cases is a typo,so after signing the contract they orally agree to modify the contract to "1,000 cases of widgets." If later the parties are in litigation concerning the amount of widgets involved in the contract,can evidence of the oral change be introduced into evidence?

A) No,since this violates the parol evidence rule.
B) Yes,since both signed the original contract.
C) Yes,since this is an exception to the parol evidence rule.
D) No,since this violates the best evidence rule.