Nonrelational databases are schema flexible and allow each record to include only the fields it needs is correct.

Nonrelational or NoSQL stores such as document and key value databases let individual records or documents vary in structure so each item can include only the fields it requires. This flexibility makes it easier to store sparse or evolving data models without altering a central schema and it supports denormalized designs that can improve read performance.

Nonrelational systems require strict data normalization to avoid duplicated information is incorrect because nonrelational systems often tolerate duplication and denormalization intentionally to optimize reads and to simplify schema evolution rather than enforcing strict normalization rules.

Nonrelational databases store data in fixed flat tables with uniform columns for every record is incorrect because that description matches traditional relational tables where every row conforms to the same set of columns and a fixed schema.

Nonrelational databases automatically provide full ACID transactions across multiple independent documents by default is incorrect because many nonrelational stores prioritize scalability and availability and either provide weaker consistency or limit transaction scope. Full multi document ACID guarantees are not a universal default for NoSQL systems.

Full AWS Practitioner Certification Question