Which AWS service or feature can the cloud practitioner use to meet this requirement?

Explanations:

AWS WAF (Web Application Firewall) is primarily used for filtering HTTP/HTTPS traffic to protect web applications, not for applying security rules at the subnet level.

Network ACLs (Access Control Lists) are used to control inbound and outbound traffic at the subnet level in a VPC, allowing or denying traffic based on rules.

Security groups act as virtual firewalls for EC2 instances, controlling inbound and outbound traffic at the instance level, not at the subnet level.

AWS Managed Services (AMS) provides operational management for AWS infrastructure but does not specifically apply security rules to subnets.