Refer to the exhibit The exhibit shows a customer deployment of two Linux instances and...

According to the AWS documentation for Transit Gateway, a Transit Gateway is a network transit hub that connects VPCs and on-premises networks. To route traffic from Linux instances to the TGW, you need to do the following steps:

In the TGW route table, associate two attachments. An attachment is a resource that connects a VPC or VPN to a Transit Gateway. By associating the attachments to the TGW route table, you enable the TGW to route traffic between the VPCs and the VPN.

In the main subnet routing table in VPC A and B, add a new route with destination 0_0.0.0/0, next hop TGW. This route directs all traffic from the Linux instances to the TGW, which can then forward it to the appropriate destination based on the TGW route table.

The other options are incorrect because:

In the TGW route table, adding route propagation to 192.168.0 0/16 is not necessary, as this is already the default route for the TGW. Route propagation allows you to automatically propagate routes from your VPC or VPN to your TGW route table.

In the main subnet routing table in VPC A and B, adding a new route with destination 0_0.0.0/0, next hop Internet gateway (IGW) is not correct, as this would bypass the TGW and send all traffic directly to the internet. An IGW is a VPC component that enables communication between instances in your VPC and the internet.

[Transit Gateways - Amazon Virtual Private Cloud]