A customer's order was sent to the incorrect warehouse for fulfillment.

Product inventory is what the sales rep should check to fulfill the order through a different warehouse. Product inventory shows the availability and location of the productin different warehouses. Checking product inventory helps to ensure that the order can be fulfilled in a timely and efficient manner, as well as to avoid any delays or errors.References:https://trailhead.salesforce.com/en/content/learn/modules/salesforce-essentials-basics/salesforce-essentials-sales-process