Which of the following is NOT a method of perfection under Article 9?

Perfection of a security interest under Article 9 of the Uniform Commercial Code (UCC) is essential for a secured party to establish priority over other creditors in a debtor's collateral. Various methods exist to achieve perfection, and understanding them is crucial.

Filing a financing statement is a common and effective method for perfecting a security interest. It puts the public on notice of the secured party's interest, thus establishing priority rights over other claims. Similarly, possession of collateral allows the secured party to perfect their interest simply by taking physical control of the property. Control, especially relevant for certain types of collateral like deposit accounts, is another recognized method of perfection as it conveys a level of security and priority.

In contrast, while delivering goods to a buyer may transfer ownership and might be part of a larger transaction, it does not serve as a method of perfection under Article 9. The mere act of delivering goods does not confer any rights or protections to a secured party regarding their security interests in the way that the other methods do. Therefore, this choice correctly identifies the option that is not recognized as a method of perfection.