Answer:
If injustice occurred/people have been treated unfairly, revolution is justified.
Explanation:
Basically if people were treated unfairly, you would feel wronged revolution is justified so basically he felt unjust
Sentence 1 is the topic sentence. other sentences are based on 1 to support sentence 1, elaborating the topic sentence.
I think it would either be A or C
4... this is the one which makes most sense