You have created a NAT gateway to ensure that instances in your private subnet can download updates from the internet. But the instances are still not able to reach the internet even after the gateway has been created. Which of the following is not the right verification that needs to be carried out to diagnose the issue?

Answer options:

A.Verify that the destination is reachable by pinging the destination from another source using a public IP address
B.Verify that the NAT gateway is in the Available state
C.Verify that the NAT gateway has been created in the private subnet
D.Make sure that the private subnet’s route table has a default route pointing to the NAT gateway

Answer - C
The NAT gateway needs to be created in the public subnet and not the private subnet
The AWS documentation mentions some of the below points which can be used to diagnose internet connectivity issues for EC2 Instances
To troubleshoot instances that can’t connect to the Internet from a private subnet using a NAT gateway, check the following:
Verify that the destination is reachable by pinging the destination from another source using a public IP address.
Verify that the NAT gateway is in the Available state. Note: A NAT gateway in the Failed state is automatically deleted after about an hour.
Make sure that you`ve created your NAT gateway in a public subnet, and that that the public route table has a default route pointing to an Internet gateway.
Make sure that the private subnet’s route table has a default route pointing to the NAT gateway.
Check that you have allowed the required protocols and ports for outbound traffic to the Internet.
For more information on EC2 Internet connectivity, please refer to the below link
https://aws.amazon.com/premiumsupport/knowledge-center/ec2-internet-connectivity/