Which AWS service will meet these requirements?

Explanations:

Amazon Inspector is a security assessment service for finding vulnerabilities in EC2 instances, not designed to protect against web exploits like SQL injections.

AWS WAF (Web Application Firewall) is designed to protect web applications from common web exploits, including SQL injection and cross-site scripting attacks.

Amazon GuardDuty provides threat detection for AWS accounts and workloads, but it does not specifically protect against web application exploits directly.

Amazon CloudWatch is a monitoring and logging service, which can monitor application performance but does not prevent web exploits such as SQL injection or XSS.