Free AWS Certified Solutions Architect Associate SAA-C03 Practice Question

The correct answer is Amazon Cognito, which allows developers to add user sign-up, sign-in, and access control to their web and mobile applications quickly and easily. It also supports federated authentication with social identity providers, such as Facebook, Google, and Amazon, which is the functionality described in the question. The other services listed have different primary uses: AWS IAM is designed for secure AWS resource management, AWS Control Tower is for governance across multiple AWS accounts, and Amazon GuardDuty specializes in security threat detection and continuous monitoring.