答案：D

考查固定句型。祈使句+连词+陈述句="If" 从句，主句。根据句意本题上下文是转折关系，所以使用or. Don’t tell a lie any more, or most people will lose faith in you.="If" you don’t tell a lie any more, most people will not lose faith in you. 句意：不要再说谎了，否则大部分人会不再相信你。