No it is no a slang , it is not that informal.
The correct answer would be choice C
Answer:
While Winston thinks about O’Brien, to whom he has never spoken at this point, he remembers a dream he had where O’Brien told him they would meet “in the place where there is no darkness.” When Winston first observes O’Brien, he believes that, like him, O’Brien is not a loyal Party member as he pretends to be. He seems to view the place where there is no darkness with a sense of hope early in the novel, leading Winston to believe that one day he would live in a world where he would be free to think and behave as he pleases.
