Which of the following would not contribute to the perfection of a secured interest?

Personal guarantees from the debtor do not contribute to the perfection of a secured interest because perfection is achieved through established methods recognized under the Uniform Commercial Code (UCC), which primarily include filing a financing statement (UCC-1), obtaining possession of the collateral, or, in certain cases, establishing control over the collateral.

To perfect a security interest, a creditor must take specific actions that put other potential creditors on notice of their claim. Filing a UCC-1 statement, for example, provides public notice of the secured party's interest in the collateral and is a common method to establish priority over competing claims. Similarly, possession of the collateral or a control agreement (used in cases involving investment property) also meets the perfection requirements. These actions ensure that the secured party has a legally recognized priority over the secured collateral in the event of the debtor's insolvency.

While personal guarantees can provide additional security and assurance from the debtor regarding repayment of the obligation, they do not affect the legal standing of the secured interest itself. Thus, they do not play a role in perfecting the security interest.