Which AWS service meets these requirements?

Explanations:

Amazon Aurora is a relational database service that offers scalability and high availability but is not specifically designed as a graph database. It supports SQL queries and is more suited for relational data rather than graph structures.

Amazon Redshift is a data warehousing service designed for large-scale analytics and is optimized for structured data queries using SQL. It is not intended for graph database use cases and does not support graph data structures.

Amazon DynamoDB is a NoSQL database service that offers high availability and scalability. However, it is a key-value and document database rather than a graph database, lacking the specialized capabilities for handling graph data and relationships effectively.

Amazon Neptune is a fully managed graph database service that supports both property graph and RDF graph models. It is designed for high availability, scalability, and optimized for graph queries, making it the correct choice for graph database requirements.