Define dangerous dogs.

• A. A dog that has barked at a stranger
• B. A dog that has killed a companion animal that is a dog or cat or inflicted serious injury, or directly caused serious injury to a person
• C. A dog that has no vaccination
• D. A dog that is chained

Answer: (B)

Dangerous dogs are defined by proven past behavior that shows they pose a real risk to safety. The key is actual harm or the direct threat of serious harm, not mere nuisance or status. The correct option reflects this because it describes a dog that has killed a companion animal (like another dog or a cat) or has inflicted serious injury, or has directly caused serious injury to a person. These outcomes show the dog’s behavior has crossed a threshold that justifies dangerous-dog designation. Barking at a stranger, lacking vaccination, or being chained do not by themselves establish that threshold, since they don’t demonstrate the level of harm or immediate danger required by the definition.