A. Modify the security groups assigned to development EC2 instances to block traffic from production EC2 instances. Modify the security groups assigned to production EC2 instances to block traffic from development EC2 instances.
B. Create a tag on each VPC attachment with a value of either production or development, according to the type of account being attached. Using the Network Manager feature of AWS Transit Gateway, create policies that restrict traffic between VPCs based on the value of this tag.
C. Create separate route tables for production and development traffic. Delete each account’s association and route propagation to the default AWS Transit Gateway route table. Attach development VPCs to the development AWS Transit Gateway route table and production VPCs to the production route table, and enable automatic route propagation on each attachment. Most Voted
D. Create a tag on each VPC attachment with a value of either production or development, according to the type of account being attached. Modify the AWS Transit Gateway routing table to route production tagged attachments to one another and development tagged attachments to one another.