I don’t know if I should have reported this as an error or not:
To me, it first seemed like it should be「これの中で」and not 「この中で」but after thinking about it, both make sense. (at least in my beginner head 
)
What’s your favorite [in the middle of this]
What’s your favorite [in this middle / in this lot]
The reason I’m unsure is because of the yellow part which is only 「の中で」. If it was the second option, shouldn’t the yellow part be「この中で」?
Nice find! Yes, you are right!
Whole 「この中で」should be highlighted.
About これの中で, although is understandable, you should use この、その、あの.
ーーー
By the way, I strongly advice writing この中で at the beging of sentence:
この中で1番好きなのはどれですか？
which is the most natural.
1番好きなのはどれですか、この中で
Are also used, but much less often.
Yep, that’s how I would write it.
I like that we get other word orders in examples on Bunpro though. It’s a nice change from textbooks.
The point is to show users that other forms appear too, so they won’t be surprised and lost if it happens. 
I agree that it’s useful, but maybe at least indicate when a sentence uses a less common phrasing?
Great idea! I will try to add notifications like that in future!
