A company is running a three-tier web application to process credit card payments. The front-end user interface consists of static webpages. The application tie...

A company is running a three-tier web application to process credit card payments. The front-end user interface consists of static webpages. The application tier can have long-running processes. The database tier uses MySQL.
The application is currently running on a single, general purpose large Amazon EC2 instance. A solutions architect needs to decouple the services to make the web application highly available.
Which solution would provide the HIGHEST availability?