Your supposed to have this in a text or movie because if you reread it you can find the letter and it will tell you everything you need to know.
The reason a writer has to write something
Here are a couple of options to choose from as to why Fitzgerald chose the title to be metaphoric of Paris:
1. <span>It represents the ruins of American "royalty" in Paris
2.</span><span> Paris is living in wealth that will end in destruction.
In either case, it has to do with wealth that no longer exists or is about to be depleted because of overuse and hedonism. Just like Babylon disappeared, this place is going to be gone soon. </span>
I don't know if I'm completely correct, so please don't get mad at me, but I do think that the answer is B. If you think about it, modern poetry has far fewer rules than it used to. Free verse has become a very popular form of poetry, and that is my reasoning. I hope this is helpful!