A contractor is installing a new irrigation system with hose bibbs. What type of backflow prevention device is required, and what is a key installation requirement regarding its height?

• A Double Check Valve Assembly (DCVA) installed at ground level
• A Reduced Pressure Principle (RP) Assembly installed at least 12 inches above grade
• An Atmospheric Vacuum Breaker (AVB) installed at least 6 inches above the highest point of use
• A Pressure Vacuum Breaker (PVB) installed at least 1 inch above the highest point of use