ACLs are an AWS service or feature that the developer can use to restrict read and write access to the S3 bucket. ACLs are access control lists that grant basic permissions to other AWS accounts or predefined groups. They can be used to grant read or write access to an S3 bucket or an object3. Security groups are virtual firewalls that control the inbound and outbound traffic for Amazon EC2 instances. They are not a service or feature that can be used to restrict access to an S3 bucket. Amazon CloudWatch is a service that provides monitoring and observability for AWS resources and applications. It can be used to collect and analyze metrics, logs, events, and alarms. It is not a service or feature that can be used to restrict access to an S3 bucket. AWS CloudTrail is a service that provides governance, compliance, and audit for AWS accounts and resources. It can be used to track and record the API calls and user activity in AWS. It is not a service or feature that can be used to restrict access to an S3 bucket.