A company deploys an application on Amazon EC2 instances in an Auto Scaling group behind...

The AWS Cloud Operations and Security documentation confirms that AWS WAF (Web Application Firewall) is designed to protect web applications from application-layer threats, including SQL injection, cross-site scripting (XSS), and other OWASP Top 10 vulnerabilities.

When integrated with an Application Load Balancer, AWS WAF inspects incoming traffic using rule groups. The AWS Managed Rules for SQL Injection Protection provide preconfigured, continuously updated filters that detect and block malicious SQL patterns.

AWS Shield (Standard or Advanced) defends against DDoS attacks, not application-layer SQL attacks, and vulnerability scanners (Option C) only detect, not prevent, exploitation.

Thus, Option D provides the correct, managed, and automated protection aligned with AWS best practices.