On July 18, Snowco, a shovel manufacturer, received an order for the purchase of 500 snow shovels from Acme, Inc., a wholesaler. Acme had mailed the purchase order on July 15. The order required shipment of the shovels no earlier than September 15 and no later than October 15. Typed conspicuously across the front of the order form was the following: "Acme, Inc., reserves the right to cancel this order at any time before September 1." Snowco's mailed response, saying "We accept your order," was received by Acme on July 21. For this question only, assume the following facts. Acme did not cancel the order, and Snowco shipped the shovels to Acme on September 15. When the shovels, conforming to the order in all respects, arrived on October 10, Acme refused to accept them. Which of the following is an accurate statement as of October 10 after Acme rejected the shovels? 
Acme's order for the shovels, even if initially illusory, became a binding promise to accept and pay for them.  Acme's order was an offer that became an option after shipment by Snowco. Acme's right to cancel was a condition subsequent, the failure of which resulted in an enforceable contract.  In view of Acme's right to cancel its order prior to September 1, the shipment of the shovels on September 15 was only an offer by Snowco. 