Which combination of AWS services would meet these requirements?

Explanations:

AWS Fargate is not necessary for handling unpredictable request patterns and scaling as required for simple key-value requests. It is more suited for containerized applications where you want to manage resources but does not directly address the requirements of the service.

AWS Lambda is well-suited for unpredictable workloads as it automatically scales to handle varying request rates, making it a good choice for services behind API Gateway.

Amazon DynamoDB is a fully managed NoSQL database service that can handle key-value requests and scale automatically to accommodate unpredictable workload patterns. It also offers flexible storage options for future growth.

While Amazon EC2 Auto Scaling can manage resource scaling, it requires more management and setup than the serverless options like AWS Lambda. It’s not optimal for services needing rapid, automatic scaling based on unpredictable traffic.

MySQL-compatible Amazon Aurora is a relational database that is better suited for complex queries rather than simple key-value requests, and while it can scale, it does not fit the requirement for unpredictable key-value data access.