What is the primary difference between Fulfillment by Amazon (FBA) and Merchant Fulfilled Network (MFN)?

Using FBA, the seller sends inventory to Amazon fulfillment centers, where its packed and shipped to customers.
Using MFN, the seller leverages Amazon facilities, expertise, and customer service.
Using MFN, inventory is stored at Amazon facilities.
Using FBA, the seller is in complete control of the handling and shipping process.

The correct answer is:

Using FBA, the seller sends inventory to Amazon fulfillment centers, where its packed and shipped to customers.