The opening video of Session 13 describes how Amazon operates. This video explains that the most expensive part of the delivery process is called: Group of answer choices The packing: putting the item in your box and taping the box shut. The cross-country shipment: moving the package, in bulk, from one location in the country to another. The tracking: the administrative and technology costs of tracking where your package is in the process. The last mile: the transportation from a delivery vehicle to your front door