Thanks for the question! So let’s walk through the argument here. We’re trying to answer a question: why are early 1700s Stradivarius violins so good? Some experts say secret varnishes, but the author dismisses this and says there’s no evidence for that. But apparently some climatologists have found that there’s some trees with special wood around where Stradivarius worked during that time, specifically wood with “special acoustic properties.” Therefore, …?
So now we’re trying to complete the argument. What follows logically? This is something we can try to come up with before we go to the answer choices. And remember, we’re trying to figure out why these violins are so good. It’s not the varnish. But there are these trees with special wood. Well, it makes sense to say that the special wood has something to do with the sound! And that’s what (D) tells us, that therefore, Stradivarius violins are so great because of the wood used to make them. We’re supposed to draw a connection between these random trees being brought up and the wood used to make the violins.
Hope this helps! Feel free to ask any other questions that you might have.