What law stipulates that a financial privacy policy must be established?

The Gramm-Leach-Bliley Act is the correct choice because it specifically requires financial institutions to establish and disclose a privacy policy to their customers. This law was enacted to streamline regulations across financial services and ensure that consumers' personal financial information is protected. It mandates that institutions inform customers about their information-sharing practices and gives consumers the right to limit the sharing of their private information.

In contrast, the Fair and Accurate Credit Transactions Act primarily aims to enhance the accuracy of consumer credit reporting. The Real Estate Settlement Procedures Act focuses on providing consumers with appropriate disclosures concerning the real estate settlement process, while the Truth in Lending Act is concerned with ensuring that consumers are provided with clear information about the terms of their credit and borrowing costs, rather than specifically focusing on privacy policies.