A,B,D.
You need External Tokenization and Dynamic data masking to meet the compliance and privacy requirements. While bot of those features are available within Enterprise Edition, Snowflakes documentation specifies to use Business critical where you have PHI and other privacy requirements.
Business Critical Edition, offers even higher levels of data protection to support the needs of organizations with extremely sensitive data, particularly PHI data that must comply with HIPAA and HITRUST CSF regulations.
It includes all the features and services of Enterprise Edition, with the addition of enhanced security and data protection. In addition, database failover/failback adds support for business continuity and disaster recovery.
https://docs.snowflake.com/en/user-guide/intro-editions