The correct answer is b. Orwell realizes that “when the white man turns tyrant, it is his own freedom he destroys.” While standing there, surrounded by 2.000 native people, he realizes that he is all alone, as an isolated figure of the conqueror - otherwise comical, now important because he has a rifle. He isn't entitled to his own, individual free will. He has to do what they expect of him. He is not a person; he is a sahib. And a sahib has to shoot when he has the rifle.