Concept:Litotes is a figure of speech that expresses an idea by negating its opposite.Explanation:The phrase “a citizen of no mean city” uses the negative word “no” with “mean,” which means insignificant.Literally, it says “not an insignificant city,” but the intended meaning is that the city is actually great and important.This indirect understatement strongly affirms a positive quality.Therefore, the expression is an example of litotes.Answer:D. litotes