please answer ASAP

Which of the following contractual agreements is NOT required to be in writing? Select one: a. Robin agrees to provide a guarantee to BMC Bank Canada in relation to the debts of ABC Corp. Inc. b. Frankie agrees to sell a Tom Thomson painting collection to Cameron for $23,000.00 C. An agreement by a homeowner to sell their home to a revenue property owner and operator d. On March 15, 2021, Fictional Co. Ltd. agrees to provide a skywriting exhibition for the City of Edmonton on July 20, 2022