Read this passage from The Phantom Tollbooth. Milo's eyes opened wide, for there in front of him was a large dog with a perfectly normal head, four feet, and a tail--and the body of a loudly ticking alarm clock.

"What are you doing here?" growled the watchdog.

What is the most likely reason why the author includes realistic elements in his description of the watchdog?

to help the reader to imagine him
to convince the reader that he exists
to persuade the reader to like him the most
to entertain the reader by making him unusual