A. Because access to production data will always be verified using passthrough credentials it is safe to mount data to any Databricks development environment.

B. All developer, testing and production code and data should exist in a single unified workspace; creating separate environments for testing and development further reduces risks.

C. In environments where interactive code will be executed, production data should only be accessible with read permissions; creating isolated databases for each environment further reduces risks.

D. Because delta Lake versions all data and supports time travel, it is not possible for user error or malicious actors to permanently delete production data, as such it is generally safe to mount production data anywhere.