You are developing a new mobile application and are considering storing user preferences in AWS.2w This
would provide a more uniform cross-device experience to users using multiple mobile devices to access the
application. The preference data for each user is estimated to be 50KB in size Additionally 5 million customers
are expected to use the application on a regular basis. The solution needs to be cost-effective, highly available,
scalable and secure, how would you design a solution to meet the above requirements?

A.
Setup an RDS MySQL instance in 2 availability zones to store the user preference data.
Deploy a public facing application on a server in front of the database to manage security and access
credentials

B.
Setup a DynamoDB table with an item for each user having the necessary attributes to hold the user
preferences. The mobile application will query the user preferences directly from the DynamoDB table.
Utilize STS. Web Identity Federation, and DynamoDB Fine Grained Access Control to authenticate and
authorize access.

C.
Setup an RDS MySQL instance with multiple read replicas in 2 availability zones to store the user
preference data .The mobile application will query the user preferences from the read replicas. Leverage
the MySQL user management and access privilege system to manage security and access credentials.

D.
Store the user preference data in S3 Setup a DynamoDB table with an item for each user and an item
attribute pointing to the user’ S3 object. The mobile application will retrieve the S3 URL from DynamoDB
and then access the S3 object directly utilize STS, Web identity Federation, and S3 ACLs to authenticate
and authorize access.