Explanation

AWS Application Migration Service (MGN) is the correct service for lift-and-shift migrations without long cutover windows because:

• Automated Migration: Automates the process of migrating physical, virtual, or cloud servers to AWS
• Minimal Downtime: Enables fast cutover windows by using block-level replication
• Lift-and-Shift Approach: Supports rehosting applications without requiring changes to the application code
• Multiple Application Support: Can migrate many applications simultaneously

Why other options are incorrect:

• AWS Application Discovery Service: Helps discover on-premises applications and their dependencies for planning migrations, but doesn't perform the actual migration
• AWS Migration Hub: Provides a central location to track migration progress across multiple AWS and partner solutions, but doesn't perform the migration itself
• AWS DataSync: Designed for data transfer and synchronization, not for migrating entire applications with their operating systems

Application Migration Service is specifically designed for the scenario described - migrating many applications with minimal downtime using a lift-and-shift approach.