You have created a VPC with an application load balancer and selected two EC2 instances as targets. However, when you are trying to make a request to the internet-facing load balancer, the request fails. What could be the reason?

Answer options:

A.The route table associated with the load balancer`s subnet does not have a route to the internet gateway.
B.Target EC2 instances are in a public subnet.
C.There is no elastic IP address attached to the load balancer.
D.Cross-zone load balancing is not enabled.

Answer: A
Option A is correct because there must be a route in a route table to the internet gateway for internet connectivity 
Option B is incorrect because this does not result in the failure mentioned in the question.
Option C is incorrect because any instances in the VPC must either have a public IP address or an attached Elastic IP address. And for the internet-facing load balancer, AWS manages the underlying IP addresses. So no need for an Elastic IP address.
Option D is incorrect because cross-zone load balancing is not a reason to cause the failure.
https://aws.amazon.com/premiumsupport/knowledge-center/create-attach-igw-vpc/