Based on the passage, Anderson puts “city” in quotation marks most likely to

"signal a nonliteral usage" is the best answer. Harlem is identified in the passage as a “neighborhood” and “in the heart of Manhattan,” not an actual city, indicating that Anderson’s use of “city” is nonliteral. The passage most strongly suggests that Harlem is a “city” in the sense that it was a place that “blacks were making their own.” The other choices are incorrect because there is no evidence in the passage that Anderson intended to introduce irony into his writing, was citing another author, or quoting dialogue.