Costco, Inc. had a contract to purchase 300,000 electric mini-Mercedes from HUMBENZ Toy Co. The toy cars were to be delivered by November 1. On October 23, the Consumer Product Safety Commission announced a recall of the toy cars as well as a ban on their sales because of electrical shorts and a high risk of fire in the cars. HUMBENZ has not delivered the cars to Costco. HUMBENZ: a. has breached its contract with Costco. b. has a void contract with Costco because the subject matter is now illegal. c. must still deliver the cars because its contract predated the recall and ban. d. none of the above