Explanation

Amazon Inspector is the correct service for this requirement because:

• Vulnerability Assessment: Amazon Inspector automatically assesses Amazon EC2 instances for software vulnerabilities and unintended network exposure
• Network Reachability Analysis: It analyzes the security groups and network configurations to identify unintended network accessibility
• Automated Security Scanning: It provides automated security assessments to help identify security vulnerabilities
• EC2 Instance Focus: Specifically designed to assess the security state of EC2 instances

Why other options are incorrect:

• AWS Config: Focuses on resource configuration compliance and auditing, not vulnerability scanning
• AWS Trusted Advisor: Provides cost optimization, performance, and security best practice recommendations, but not detailed vulnerability scanning
• AWS Shield: A DDoS protection service, not a vulnerability assessment tool

Amazon Inspector generates detailed findings with severity levels and remediation steps, making it ideal for identifying security vulnerabilities and unintended network access on EC2 instances.