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

Explanations:

AWS Config is primarily used for tracking resource configurations and changes over time, but it does not monitor service quotas or provide notifications based on usage metrics.

AWS CloudTrail records API calls and provides event logging for AWS accounts, but it does not monitor service quota usage or send notifications based on specific thresholds.

AWS Trusted Advisor helps monitor AWS service limits and quotas, providing alerts when usage approaches or exceeds specified thresholds, making it the appropriate choice for this requirement.

AWS Lambda is a serverless compute service that runs code in response to events, but it does not inherently monitor service quotas or provide notifications. It could be used in conjunction with other services to process notifications, but it does not fulfill the requirement by itself.