A Company is currently hosting an application that connects to a MySQL AWS RDS Instance. Of late, there have been many performance issues being encountered. After careful analysis, it has been determined that the issue is occurring due to the static (same) queries being fired against the database. Which of the following can be added to the architecture to enhance the performance?

Answer options:

A.Enable Multi-AZ for the database.
B.Use the ElastiCache Service.
C.Use Read Replica.
D.Use CloudFront in front of the database.

Answer – B
ElastiCache can be used to reduce the latency of requests as it is returning values directly from RAM.
A read replica is more suitable for frequently changing, or dynamic queries. 
Up-to-dateness of data:
A read replica will continuously sync from the master. So your results will probably lag 0 - 3s (depending on the load) behind the master.
A cache takes the query result at a specific point in time and stores it for a certain amount of time.
Performance:
A cache can only return results for queries it has already seen. So if you run the same queries over and over again, it`s a good match.
If you have many different, frequently changing, or dynamic queries, a read replica will be a better match.
ElastiCache should be much faster since it`s returning values directly from RAM. However, this also limits the number of results you can store.
Option A is incorrect since this is used for the high availability of the database.
Option C is incorrect since using read replica is not suitable as mentioned above.
Option D is incorrect since CloudFront can be used forWeb distributions, not for caching.
For more information on ElastiCache, please refer to the below URL-
https://aws.amazon.com/elasticache