Regularly use SHA-256 to hash the directory containing the sensitive information. Monitor the files for unauthorized changes. This option is the best technique to ensure the integrity of the files and tie any changes to a specific user session. Hashing is a process that generates a unique value for a given input, and any modification to the input will result in a different hash value. By using SHA-256, which is a secure hashing algorithm, the analyst can compare the hash values of the files before and after each user session and detect any unauthorized changes.