I think it is the first answer, because an allusion is something like a hallucination, which means you are seeing things that are not real, and spring wind can't actually dance through trees in real life, making it an allusion. I hope this helps!!
The phrase <em>with exciting plots </em>is used as D. adjective phrase, because it modifies the noun <em>books. </em>What kind of books? - (The ones) with exciting plots. <em> </em>
