A company runs its current application that has a million views per day, entirely on-premises. However, they expect a big boost in traffic and need to figure out a way to decrease the load to handle the scale. Unfortunately, they cannot migrate their application to AWS. What could they do with their current on-premises application to help offload some of the traffic and scale to meet the demand cost-effectively? Choose the correct answer from the options below.

Answer options:

A.Deploy OpsWorks on-premise to manage the instance to configure on-premise auto-scaling to meet the demand.
B.Upload all static files to Amazon S3 and create a CloudFront distribution serving those static files.
C.Duplicate half your web infrastructure on AWS, offload the DNS to Route 53 and configure weighted-based DNS routing to send half the traffic to AWS.
D.Create a CloudFront CDN and enable query string forwarding. Offload the DNS to AWS to handle CloudFront CDN traffic but use on-premise load balancers as the origin.

Answer – D
The main point to consider is that the application should entirely stay on the on-premises server but still leverage AWS offerings for handling the peak traffic and scale on demand. CloudFront is the best suited for such a situation because it can use the on-premises server as the custom origin.
Option A is incorrect because even though OpsWork can work with on-premises servers, setting up the EC2 instances with Auto Scaling would be a costly solution.
Option B is incorrect because moving static files to S3 is not sufficient ( since the application has a million views per day ) to improve the scalability to handle the peak load. How to handle the dynamic contents is not mentioned in this option.
Option C is incorrect because the requirement explicitly mentions that the application cannot be migrated to AWS.
Option D is CORRECT because CloudFront - which is an AWS managed - is a highly available, scalable service that can use the on-premises server as the origin. By enabling the "Query String Forwarding" with a value of "None" will increase the likelihood that CloudFront can serve a request from the cache, which improves performance and reduces the load on your origin. Amazon CloudFront can speed up the distribution of both the static and dynamic web content as it delivers the content through a worldwide network (edge locations).
Refer to page 52 on the below link- 
https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/AmazonCloudFront_DevGuide.pdf