A. B. Zook Incorporated is a manufacturer of washing machines. Over the telephone, Zook offers to sell Radar Appliances one hundred model Z washers at a price of $150 per unit. Zook agrees to keep the offer open for ninety days. Radar tells Zook that the offer appears to be a good one and that it will let Zook know of its acceptance within the next two or three weeks. One week later, Zook sends and Radar receives notice that Zook has withdrawn its offer. Radar immediately thereafter telephones Zook and accepts the $150 per unit offer. Zook claims, first, that no sales contract was ever formed between it and Radar and second, that if there is a contract, the contract is unenforceable.