Why is Amazon DynamoDB service best-suited for implementation in mobile, Internet of Things (IoT) and gaming applications?

Answer options:

A.DynamoDB is a fully-managed database instance with no infrastructure overheads.
B.DynamoDB has a flexible data model and single-digit millisecond latency.
C.Whilst in operation, DynamoDB instances are spread across at least three geographically distinct centers, AWS Regions.
D.DynamoDB supports eventual and strongly consistent reads.

Correct Answer – B
The use cases mentioned in the scenario have unstructured data in common. Therefore, the most appropriate attribute of Amazon DynamoDB is its flexible data model and single-digit millisecond latency.
https://aws.amazon.com/blogs/database/how-to-determine-if-amazon-dynamodb-is-appropriate-for-your-needs-and-then-plan-your-migration/
Option A is INCORRECT because being fully-managed and having no infrastructure overheads do not distinguish DynamoDB as the best-suited solution for the given use cases.
Option C is INCORRECT because the aspect of fault-tolerance, disaster recovery and high availability is also present in Amazon Relational Databases (RDS). This feature does not distinguish the service in accordance with the described use cases.
Option D is INCORRECT because this attribute of DynamoDB does not fully justify its exclusive choice over other instances when considered for implementation in the use cases mentioned in the question.