Final answer:
Hashing database fields is not a standard requirement for cloud applications, unlike encryption and data masking, which are crucial for data security.
Step-by-step explanation:
Software developers designing applications for the cloud should include options to ensure various security measures, but there is one option listed that is not typically a requirement for cloud applications. That option is b. hashing database fields. While encryption of data at rest (option a) and encryption of data in transit (option c) are critical for protecting data against unauthorized access, and data masking (option d) can protect sensitive information from being exposed to unauthorized personnel, hashing database fields is more of a specific technique used within certain aspects of security such as storing passwords securely, rather than a broad capability expected in cloud applications.