PCI DSS (Payment Card Industry Data Security Standard) is the most appropriate governance framework when collecting and processing credit card data, including international user data. PCI DSS establishes security standards for organizations that handle payment card transactions and ensures the protection of cardholder data globally. The other options, such as ISO 27001 and NIST 800-53, provide general security frameworks, but PCI DSS is specifically designed for payment card security, which is critical when handling credit card information.