You have a set of instances setup in an AWS VPC. You need to ensure that instances in the VPC receive host names from the AWS DNS. You have set the enableDnsHostname attribute set to true for your VPC. But the instances are still not receiving the host names when they are being launched. What could be the underlying issue.

Answer options:

A.The Auto-Assign Public IP is not set for the Subnet in which the Instance is launched
B.The enableDnsSupport is not set to true for the VPC
C.You need to configure a Route 53 private hosted zone first
D.You need to configure a Route 53 public hosted zone first

Answer – B
You need to set both values for instances to receive DNS hostnames. This is also given in the AWS Documentation
For more information on using VPC DNS , please refer to the below URL
https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-dns.html