How can a solutions architect make the system more responsive?

A web application runs on Amazon EC2 instances behind an Application Load Balancer. The application allows users to create custom reports of historical weather data. Generating a report can take up to 5 minutes. These long-running requests use many of the available incoming connections, making the system unresponsive to other users

How can a solutions architect make the system more responsive?
A . Use Amazon SOS with AWS Lambda to generate reports
B . Increase the Idle timeout on the Application Load Balancer to 5 minutes.
C . Update the client-side application code to increase its request timeout to 5 minutes.
D . Publish the reports to Amazon S3 and use Amazon CloudFront for downloading lo the user.

Answer: A