Context: This week she turned 13 . She is still a puppy at heart , but her body has slowed down considerably . Her hips bother her and the stairs are difficult to navigate .
Question: What may be the reason the stairs are hard to navigate .
Option 0: None of the above choices .
Option 1: The dog is sick .
Option 2: The dog is old .
Option 3: The dog is lazy .
Answer: 2