Someone on your team configured a Virtual Private Cloud with two public subnets in two separate AZs and two private subnets in two separate AZs. Each public subnet AZ has a matching private subnet AZ. The VPC and its subnets are properly configured. There are multiple webserver instances in the private subnet. You are told to set up a public-facing Elastic Load Balancer in the public subnets to accept requests from clients and distribute those requests to the webserver instances. How can you set this up?

Answer options:

A.Select both of the private subnets which contain the webserver instances when configuring the ELB.B.Move the webserver instances from the public subnets to the private subnets and then configure the ELB with those subnets.
C.Select both of the public subnets when configuring the ELB.D.You can`t. The ELB must be in the same private subnets as the webserver instances.

Answer – C
Option A is incorrect because you need to set up the internet-facing load balancer. So the public subnets need to be associated.
Option B is incorrect because web servers need to remain in the private subnets. There is no need to shifting them to the public subnet.
Option C is CORRECT because you need to associate the public subnets with the internet-facing load balancer. You would also need to ensure that the security group of the load balancer has the listener ports open and the security groups of the private instances allow traffic on the listener ports and the health check ports.
Option D is incorrect because you can configure the internet-facing load balancer with the public subnet. 
For more information on the AWS ELB, please refer to the below links.
https://aws.amazon.com/premiumsupport/knowledge-center/public-load-balancer-private-ec2/
https://aws.amazon.com/elasticloadbalancing/classicloadbalancer/