During December, Willow Appliance Company sold appliances to Ragnar Company for $25,000. Willow is unable to determine Ragnar's ability to pay the amount owing. Ragnar pays the full amount due in February of the following year. Willow uses the earnings approach to revenue recognition. Identify the critical event that will trigger revenue recognition. Prepare the journal entry to record the shipment of goods to Ragnar. The goods cost Willow $19,000 and Willow uses a perpetual inventory system.