If he occurs at length in this account, it is because he contributed much to the trip. A dog, particularly an exotic like Charley, is a bond between strangers. Which statement best paraphrases the author’s stated reason in this passage for describing Charley the poodle at great length?

He is a large dog, so it takes a long time to describe him.
The length of the description emphasizes his importance to the story.
The author wants to show how much he loves his dog.
The dog is unusual, so it is necessary to explain how he is special.