What functionality does Amazon Cognito provide for user management?

Amazon Cognito is primarily used for user management in applications by providing the capability to create and manage unique identities and handle authentication. It allows developers to integrate user sign-up, sign-in, and access control into their applications easily. With Cognito, it is possible to authenticate users through social identity providers like Facebook, Google, or Amazon, as well as through a custom username and password.

The service also supports user pools, which are dedicated user directories where users can be managed, ensuring secure sign-in and access to resources across applications. By enabling secure authentication mechanisms and managing user profiles, Amazon Cognito simplifies the handling of user identities, making it a robust option for managing authentication in web and mobile applications.

The other options relate to functionalities that fall outside the scope of user management. Centralized management of multiple AWS accounts pertains to AWS Organizations, security monitoring relates to services like AWS CloudTrail or AWS Config, and protection of sensitive data through encryption is the focus of AWS Key Management Service (KMS) and other data security services. Thus, the correct choice emphasizes the core capabilities of Amazon Cognito as a user management solution.