Continuous monitoring requires an always-on compliance service that evaluates resources over time. AWS Config provides managed rules that assess configuration state and compliance continuously. AWS Certified Security – Specialty guidance highlights AWS Config for continuous compliance across accounts and regions when used with AWS Organizations. The ec2-managedinstance-applications-required managed rule evaluates whether specified software is installed on managed instances, leveraging Systems Manager inventory/managed instance status. By enabling AWS Config organization-wide and deploying this managed rule across all accounts, the company can continuously evaluate both existing and newly launched instances for required application presence. This provides a consistent compliance dashboard and history of compliance changes. Option D can provide inventory lists, but it is not a compliance rule engine that flags noncompliance with the same governance reporting and remediation pathways. Options B and C are operational approaches but do not provide continuous compliance state across the organization.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Config Managed Rules for EC2 and SSM Managed Instances

AWS Organizations Integration with AWS Config