A company is experiencing growth as demand for its product has increased. The company's existing purchasing application is slow when traffic spikes. The application is a monolithic three-tier application that uses synchronous transactions and sometimes sees bottlenecks in the application tier. A solutions architect needs to design a solution that can meet required application response times while accounting for traffic volume spikes.
Which solution will meet these requirements?

A. Vertically scale the application instance using a larger Amazon EC2 instance size. B. Scale the application's persistence layer horizontally by introducing Oracle RAC on AWS. C. Scale the web and application tiers horizontally using Auto Scaling groups and an Application Load Balancer. D. Decouple the application and data tiers using Amazon Simple Queue Service (Amazon SQS) with asynchronous AWS Lambda calls.