Which AWS service or feature can a company use to apply security rules to specific Amazon EC2 instances?

Explanations:

Network ACLs are associated with subnets, applying rules at the subnet level, not to individual EC2 instances.

Security groups act as virtual firewalls at the instance level, allowing specific rules for each EC2 instance.

AWS Trusted Advisor provides recommendations to improve performance and security but does not directly apply security rules.

AWS WAF is used for filtering web traffic to applications, but it does not apply security rules to EC2 instances.