Answer: C) Straps attached tot he dogs to allow them to pull the sled.
Explanation:
Since the sentence indicates the dogs were running for 12 hours, you can assume they were dog sledders. Option A does not make sense for the sentence. Option B could work theoretically, however, I do not know anyone that walks their dogs for 12 hours. Also, walking vs running is the key word here. Option D does to apply since the answer is C.
