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 .

Based on the preceding passage, choose your answer for question What may be the reason the stairs are hard to navigate .
Available choices: i. None of the above choices .. ii. The dog is sick .. iii. The dog is old .. iv. The dog is lazy ..
The answer is:
iii.