Acme Builders, Inc. began constructing and developing a beach resort and condominiums in Gulf Shores, Alabama, earlier this year. Out of all the documents and contracts that the company handles for this project, which of the ones listed below is not governed by the Uniform Commercial Code $($UCC$)$:

Contracts for the supply of concrete, timber, and other construction materials.

Contract for the sale of condominiums.

Leases of excavators, bulldozers, and other heavy machinery for a construction project.

Letters of credit from the bank.