Strong isolation of sensitive production data from development environments is best achieved using separate Snowflake accounts. Account-level isolation ensures independent security boundaries, network policies, and governance controls. Secure Data Sharing allows controlled, read-only access to production data without copying it, supporting safe data transfer between environments (Answer A).
Using cloning across accounts is not supported; cloning works only within the same account. Database-level separation does not provide the same security guarantees as account-level isolation, and user-level network policies are not supported in Snowflake.
This design aligns with SnowPro Architect best practices for regulated industries, emphasizing strong isolation, least privilege, and secure data access mechanisms.