The last one is the answer
The dark cloud was like a stain of darkness over the wide-open plain.
(Is that too advanced?)
There was a red stain on the boy's shirt as he stood in the grassy plain.
(That's a bit simpler.)
An autobiography is about the truth and a story about one’s life The answer would be an autobiography is a type of narrative nonfiction.
I believe the correct choice of answer would be A. Hope this helps!