How best can you scale this in a simple way?

You need to scale an RDS deployment. You are operating at 10% writes and 90% reads, based on your logging. How
best can you scale this in a simple way?

A.
Create a second master RDS instance and peer the RDS groups.

B.
Cache all the database responses on the read side with CloudFront.

C.
Create read replicas for RDS since the load is mostly reads.

D.
Create a Multi-AZ RDS installs and route read traffic to standby.

Explanation:
The high-availability feature is not a scaling solution for read-only scenarios; you cannot use a standby replica to serve
read traffic. To service read-only traffic, you should use a Read Replica. For more information, see Working with
PostgreSQL, MySQL, and MariaDB Read Replicas.
http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concepts.MultiAZ.html