Answer:
inactive
Step-by-step explanation:
The underlined word in the passage is "listless." The context clues in the passage suggest that the dogs have become less energetic and less active. They are described as being "huddled together so tightly" and "seemed to be a single enormous beast at rest." This is in contrast to the beginning of the journey, where the dogs were "rowdy" and "often scrapping among themselves."
Given these contextual clues, the correct definition for the word "listless" in this passage is "inactive."