How should a solutions architect resolve this issue with the LEAST amount of application changes?

A company has multiple applications that use Amazon RDS lor MySQL as is database. The company recently discovered that a new custom reporting application has Increased the number of Queries on the database. This is slowing down performance.

How should a solutions architect resolve this issue with the LEAST amount of application changes?
A . Add a secondary DB instance using Multi-AZ
B . Set up a road replica ana Multi-AZ on Amazon RD
D . Set up a standby replica and Multi-AZ on Amazon RDS
E . Use caching on Amazon RDS to improve the overall performance

Answer: D