Explanation

AWS Firewall Manager is the correct service for managing security groups across multiple AWS accounts in one centralized place.

Why AWS Firewall Manager?

• Centralized Security Management: Firewall Manager allows you to centrally configure and manage firewall rules across multiple AWS accounts and resources
• Security Group Management: Specifically designed to manage security groups, web ACLs, AWS Shield Advanced, and VPC security groups across your organization
• Cross-Account Management: Works with AWS Organizations to provide security policy management across all accounts in your organization

Why not the other options?

• AWS Config: Primarily for compliance auditing and resource configuration tracking, not for centralized security group management
• AWS Organizations: Used for account management and policy-based management, but doesn't provide specialized security group management capabilities
• AWS Trusted Advisor: Provides best practice recommendations and cost optimization advice, but doesn't offer centralized security group management

Key Benefits of AWS Firewall Manager:

• Automate security group administration
• Enforce consistent security policies
• Monitor compliance across all accounts
• Simplify security management at scale