Google Cloud Armor is specifically designed to protect applications from distributed denial-of-service (DDoS) and application layer (Layer 7) attacks. By configuring a Google Cloud Armor security policy and attaching it to the backend service of the global HTTP(S) load balancer, you can define rules to filter malicious traffic, block specific IP ranges, and leverage pre-configured rules for common attacks. VPC Service Controls (A) focus on data exfiltration prevention, not attack mitigation. VPC firewall rules (C) and hierarchical firewall rules (D) operate at lower network layers (e.g., IP/ports) and are insufficient for Layer 7 attack protection. Google's infrastructure already provides baseline DDoS protection, but Cloud Armor adds advanced security for application-specific threats.