Explanation

AWS Database Migration Service (AWS DMS) is specifically designed for migrating databases to AWS with minimal downtime. Here's why it's the correct choice:

Key Features of AWS DMS:

• Minimal Downtime: Uses continuous data replication during the migration process, allowing the source database to remain operational
• Database Support: Supports homogeneous migrations (same database engine) and heterogeneous migrations (different database engines)
• Secure: Provides encryption in transit and at rest
• Automated: Handles schema conversion and data type mapping
• Continuous Replication: Can maintain synchronization between source and target databases

Why Other Options Are Incorrect:

• AWS Snow Family: Used for offline data transfer of large datasets, not for live database migration with minimal downtime
• AWS DataSync: Designed for moving file system data between on-premises and AWS, not database migration
• AWS Mainframe Modernization: Focused on modernizing mainframe applications, not general database migration

AWS DMS is the ideal service for securely rehosting databases to AWS while maintaining business continuity through minimal downtime.