Your company has a set of EC2 Instances that are placed behind an ELB. Some of the applications hosted on these instances communicate via a legacy protocol and port. There is a security mandate that all traffic between the client and the EC2 Instances needs to be encrypted with SSL. Which of the following options can achieve the requirements?

Answer options:

A.Use an Application Load balancer and terminate the SSL connection at the ELB.B.Use a Classic Load balancer and terminate the SSL connection at the ELB.C.Use an Application Load balancer and terminate the SSL connection at the EC2 Instances.
D.Use a Classic Load balancer and terminate the SSL connection at the EC2 Instances.

Answer: D
Option A is incorrect because you need to use a Classic Load balancer since some applications communicate via a legacy protocol.
Option B is incorrect since the SSL encryption is required for the application in the EC2 Instances. The SSL should not be terminated at the load balancer.
Option C is incorrect because you need to use a Classic Load balancer since some applications communicate via a legacy protocol.
Option D is CORRECT because since there are applications that work on legacy protocols, you need to ensure that the ELB can be used at the network layer as well. Hence you should choose the Classic LB. Since the traffic needs to be secure between the Client and the EC2 Instances, the SSL termination should occur on the EC2 Instances.
For more information on HTTPS listeners for classic load balancers, please refer to the below URL:
https://docs.aws.amazon.com/elasticloadbalancing/latest/classic/elb-https-load-balancers.html