Which of the following methods to secure credit card data is best to use when a requirement is to see only the last four numbers on a credit card?

Masking is the best method because it replaces sensitive data with non-sensitive substitutes while maintaining the original data's format and usability. This allows users to see only the last four digits of a credit card number, fulfilling the specific requirement. Encryption would obscure the entire number, making even the last four digits unreadable without decryption. Hashing creates a fixed-size string that cannot be reversed to reveal any part of the original data. Tokenization replaces the entire credit card number with a unique, non-sensitive token, which also wouldn't directly display the last four digits of the original card.