What solution will allow Amazon QuickSight in ap-northeast-1 to access Amazon Redshift in us-east-1?

To enable Amazon QuickSight in one AWS region to access Amazon Redshift in another region, creating a security group with the appropriate rules for access is essential. When QuickSight needs to communicate with Redshift, it must have the necessary permissions set up to ensure secure connectivity. A security group acts as a virtual firewall that controls incoming and outgoing traffic to your resources. By defining the security group with rules that allow traffic from the QuickSight IP ranges, you can facilitate the connection between QuickSight in the ap-northeast-1 region and Redshift in the us-east-1 region.

Other options don't directly address the need for proper connectivity. Cross-region snapshots do not facilitate real-time access; they are primarily for data backup and recovery. A VPN connection may provide a secure channel between regions, but it is not the most efficient solution for QuickSight to access Redshift, as it requires more complex setup and is not inherently necessary. Using Amazon CloudFront is inappropriate in this context, as it is a content delivery network designed for distributing web content, not for directly enabling database access. Thus, effective communication between services across regions relies significantly on correctly configured security measures like security groups.