How does H. T. Johnson use sarcasm in his poem "The Black Man's Burden"?

This question had choices. These are the missing choices.

A. He ridicules Britain's soft-hearted dealings with the natives, who have shown only hard-hearted aggression towards civilization.

B. He scorns the concept of labeling people by their skin color by labeling people "Red" and "Brown."

C. He says that the British have solved the "Black Man's" problems but have created their own "White Man" problems.

D. He says that the natives tolerate the imperialist armies' rifles, which are actually killing the natives.

After reading the poem, the only answer choice that makes sense to me is:

D. He says that the natives tolerate the imperialist armies' rifles, which are actually killing the natives.