On this Sunday morning, Sally had actually been hoping to sleep in. But her dog Arco started barking early in the morning. She shouted at him to be quiet. Arco barked even louder. In fact, he seemed to bark louder every time Sally yelled.

Why didn't Arco stop barking when Sally told him to?



1. Arco thought his owner had finally gotten enough sense to bark and to help protect their territory
   
   
2. Arco can't hear
   
   
3. Arco likes to get on Sally's nerves and did it on purpose