Correct answer only ! how is the underlined prepositional phrase in this sentence being used?

- "the answers are a and b.  

when cullen speaks of planting while others reap, and standing "abject and mute," he is speaking about the racial injustices present in american society. as these injustices have changed over time, the american identity  has also shifted. those changes are, in turn, reflected in american literature."

3 is blunder, i’m not sure about the last one but the first two look correct

explanation:

the answer to your question is d because the clause conveys the tone of the man in the excerpt, which is arrogant and cocky. hope that .