The best way to ensure data is properly sanitized while in cloud storage is to cryptographically scramble the data. Cryptographic scrambling is the process of transforming data into an unreadable form using a secret key or algorithm. Cryptographic scrambling protects the data from unauthorized access, modification, or deletion, even if the cloud storage provider or a third party gains access to the data. Cryptographic scrambling also ensures that the data can be restored to its original form using the same key or algorithm, if needed. The other options are not as effective as cryptographic scrambling, because they either do not completely remove the data,or they make it impossible to recover the data. References = Risk and Information Systems Control Study Manual, Chapter 3, Section 3.3.1, page 3-21.