Which AWS service should the company use to meet this requirement?

Explanations:

Amazon CloudWatch is primarily used for monitoring and logging metrics, not for tracking access or actions performed on AWS services.

AWS CloudTrail is designed specifically to log and monitor account activity related to actions taken on AWS services, making it ideal for tracking who accessed a service and what actions were performed.

AWS Security Hub provides a centralized view of security alerts and compliance status, but it does not track individual user access or actions in AWS services.

Amazon Inspector is a security assessment service that helps improve the security and compliance of applications, but it does not track user access or actions on AWS services.