The correct answer is B) antonyms.
The words "gentle" and "violence" in Mao's statements are used as antonyms.
In grammatical terms, an antonym is a word that means the opposite of another word. "Anti" means against. "Onym," name. For instance, night-day, big-small, tall-short. In this case, "gentle" means being kindly whereas "violence" is something rude or aggressive.