Think about possible counterclaims from reliable sources.
Firstly, which unit? Secondly, scientists are usually hard working but they can be arrogant. The answer is probably c.
Adjective, frail·er, frail·est.
having delicate health; not robust; weak:
My grandfather is rather frail now.
easily broken or destroyed; fragile.
Answer:
The bird in the story brings life back to the family after the the family experienced A LOT of bad things.
Explanation: