What policy setting should be selected for a new host when it has an existing...

The correct setting is Moderate Level ML . Falcon’s prevention policy guidance recommends Moderate for most use cases, and the staged deployment model for environments with pre-existing antivirus begins with Phase 1, where machine-learning prevention is conservative while detection is used to triage and tune. The important CCFA concept is not to begin with Extra Aggressive or Aggressive prevention on a newly deployed host with another antivirus product, because that increases false-positive and compatibility risk. Cautious detects only when confidence is very high, but Falcon’s recommended baseline for practical protection is Moderate. The course guide states that Moderate detects or prevents when the machine-learning system has moderate confidence and is recommended for most use cases, while Extra Aggressive is not recommended outside penetration testing scenarios.