Which AWS service will meet these requirements?

Explanations:

Amazon GuardDuty is used for threat detection and monitoring malicious activity, not specifically for scanning software vulnerabilities.

Amazon Inspector is designed to automatically scan EC2 instances for software vulnerabilities and provide findings on security issues.

Amazon Detective helps with analyzing and investigating security findings but does not scan for software vulnerabilities.

Amazon Cognito is a service for managing user authentication and access, unrelated to vulnerability scanning.