A company is running a large application on premises. Its technology stack consists of Microsoft .NET for the web server platform and Apache Cassandra for the database. The company wants to migrate this application to AWS to improve service reliability. The IT team also wants to reduce the time it spends on capacity management and maintenance of this infrastructure. The Development team is willing and available to make code changes to support the migration.
Which design is the LEAST complex to manage after the migration?

A. Migrate the web servers to Amazon EC2 instances in an Auto Scaling group that is running .NET. Migrate the existing Cassandra database to Amazon Aurora with multiple read replicas, and run both in a Multi-AZ mode.
B. Migrate the web servers to an AWS Elastic Beanstalk environment that is running the .NET platform in a Multi-AZ Auto Scaling configuration. Migrate the Cassandra database to Amazon EC2 instances that are running in a Multi-AZ configuration.
C. Migrate the web servers to an AWS Elastic Beanstalk environment that is running the .NET platform in a Multi-AZ Auto Scaling configuration. Migrate the existing Cassandra database to Amazon DynamoDB.
D. Migrate the web servers to Amazon EC2 instances in an Auto Scaling group that is running .NET. Migrate the existing Cassandra database to Amazon DynamoDB.