Which of the following is used to conceal credit card information in a database log file?

Masking is the correct answer because it involves replacing sensitive data, like credit card numbers, with non-sensitive but realistic-looking data. This allows the data to be used for testing or analysis while protecting the actual sensitive information. Tokenization replaces sensitive data with a unique, non-sensitive token, which is often used in payment processing but the original data is stored elsewhere, not necessarily concealed in a log file itself. Hashing creates a fixed-size string of characters from input data, which is one-way and irreversible, making it unsuitable for scenarios where the original data might need to be retrieved or partially viewed. Obfuscation makes data difficult to understand but doesn't necessarily replace it with non-sensitive data in a structured way for log files.