C: Using separate Snowflake accounts for development, test, and production environments allows for tailored RBAC configurations without intermingling roles and permissions. This separation can simplify access management and enhance security, leading to cost-effective administration and compliance with organizational policies. D: If the security policy requires different AD instances for various environments, maintaining separate Snowflake accounts is essential. This segregation ensures that each environment adheres to its specific security requirements, reducing complexity and potential security risks, thus optimizing costs related to security management and compliance.