Explanation

AWS Transit Gateway is the correct solution because it acts as a central hub that can connect multiple VPCs and on-premises networks through a single network connection.

Why AWS Transit Gateway?

• Centralized Hub: Acts as a single connection point for multiple VPCs and on-premises networks
• Simplified Network Management: Reduces the complexity of managing multiple point-to-point connections
• Scalability: Can connect thousands of VPCs and on-premises networks
• Route Management: Provides centralized routing between different network segments

Why not the other options?

• AWS Direct Connect: Provides dedicated network connection from on-premises to AWS, but doesn't inherently connect multiple VPCs through a single connection
• VPC Peering: Connects two VPCs directly, but doesn't provide a centralized hub for multiple VPCs and on-premises networks
• AWS Client VPN: Provides secure remote access for individual users, not for connecting multiple networks

This solution is ideal for organizations that need to manage complex network architectures with multiple VPCs and hybrid cloud connectivity.