Your first introduction to intellectual property law. For a weaken question, we start with the argument core:
Grey used the same unusual metaphor that Jordan used in a book published earlier + They couldn't both have invented it ---> Grey read Jordan's book
What's the gap? Well what if they both plagiarized the metaphor from a third author? You get that in (A). If they both independently stole it, there's no reason to believe that Jordan read Grey's book.
Wrong answers:
(B) is irrelevant. We have to come up with another explanation as to how Grey heard about the metaphor. The fact that Grey is using the unusual metaphor in a new way doesn't explain where she got it.
(C) is even more irrelevant. We're worried with where the metaphor came from, not who the books were written for.
(D) does nothing to the argument. Jordan re-using the metaphor doesn't explain where Grey got it.
(E) confuses the issue. The fact that Grey was generally more creative doesn't answer whether Grey stole this particular unusual metaphor.
I hope this helps. If you still have questions after reading this, post away!
Demetri