You have a web application hosted on an EC2 Instance in AWS that users can access across the globe. The Operations team has been receiving support requests about extreme slowness from users in some regions. What can be done to the architecture to improve the response time for these users?

Answer options:

A.Add more EC2 Instances to support the load.
B.Change the Instance type to a higher instance type.
C.Add Route 53 health checks to improve the performance.
D.Place the EC2 Instance behind CloudFront.

Correct Answer – D
AWS Documentation mentions the following:
Amazon CloudFront is a web service that speeds up distribution of your static and dynamic web content, such as .html, .css, .js, and image files to your users. CloudFront delivers your content through a worldwide network of data centers called edge locations. When a user requests content that you`re serving with CloudFront, the user is routed to the edge location that provides the lowest latency (time delay) so that content is delivered with the best possible performance.
For more information on Amazon CloudFront, please refer to the below URL:
https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/Introduction.html
Option A is incorrect. The latency issue is experienced by people from certain parts of the world only. So, increasing the number of EC2 Instances or increasing the instance size will not make much difference. 
Option B is incorrect.The latency issue is experienced by people from certain parts of the world only. So, changing the Instance type to a higher instance type will not make much difference.
Option C is incorrect. Route 53 health checks are meant to see whether the instance status is healthy or not. 
Since this case deals with responding to users` requests, we do not have to worry about this. However, for improving latency issues, CloudFront is a good solution.