What was martin luther king, jr., referencing in the passage that brought him to lead a protest in birmingham?

Mr. Martin Luther King Jr. was a social activist and baptist minister who played a key role in the Americans civil rights movement from the mid 1950s until his assassination  in 1968.

The passage that brought him to lead a protest in Birmingham  according the his letter from the jail: "There are just laws and there are unjust laws  I would agree with St. Augustine that an unjust law is not a law at all" and he cited to Mr. Thomas Aquinas an unjust law is a human law that is not rooted in eternal and natural law.

c is the correct answer for this question.

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