Correct Answer: DTo fulfill the requirement of encrypting widely-used standard fields while still being able to use these fields in workflow rules, Shield Platform Encryption is the best solution. Shield Platform Encryption allows for more advanced encryption capabilities and is designed to securely store data and still allow it to be usable in various Salesforce features, including workflow rules. Classic Encryption does not support encrypting standard fields and other options like Cryptography Class and Data Masking do not meet the requirement of usable encryption in workflow rules.