Poll Suggestion: Laura Poitras, Oscar-Winning Documentarian

Which of the following documentaries*, as directed or co-directed by Oscar-winning documentarian Laura Poitras, is the most powerful?

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LIST:  https://www.imdb.com/list/ls4152455705/

LIST (copy):  https://www.imdb.com/list/ls4152455705/copy

POLL: 

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*Feature-length documentaries only; no short films.