Which AWS tool or service can be used to meet these requirements?

Explanations:

Amazon CloudWatch is primarily used for monitoring AWS resources and applications, providing metrics and logs. It does not specifically track API calls made against AWS resources.

Amazon Inspector is a security assessment service that helps improve the security and compliance of applications deployed on AWS. It does not track API calls or account activity.

AWS CloudTrail is designed specifically for logging and monitoring API calls made against AWS resources. It provides detailed event logs that help track changes and activity within AWS accounts.

AWS IAM (Identity and Access Management) is used to manage access and permissions for AWS resources but does not track API call activity or provide logs of API actions.