Final answer:
The NAR code of ethics, established in 1913, is the oldest ethics code for real estate professionals, predating other codes like the TAR code of ethics, Texas Property Code, and Texas Administrative Code.
Step-by-step explanation:
The oldest code of ethics for real estate professionals is the NAR code of ethics. Established in 1913 by the National Association of Realtors (then called the National Association of Real Estate Exchanges), it predates the other codes listed, such as the TAR code of ethics, Texas Property Code, and Texas Administrative Code. The NAR code of ethics sets forth a set of duties that realtors owe to their clients, the public, and other realtors, and it has been an important part of professional standards in the real estate industry for over a century