"Brother! Come quickly!"
Translation:형! 빨리 와!
I answered "동생, 빨리 와" as there was no specification of age (younger or older brother). Also, I felt it was more natural to use the informal form with your younger sibling rather than the older one. I'd think the use of the form 요 would be more appropriate to talk to a "hyung" hence my decision to pick the word "dongsaeng". It got marked as wrong. I reported it as I think this answer should be allowed.