There was a misunderstanding about a trifle and I had to resign.
【正确答案】 B
【答案解析】解析:题干中trifle“琐事”,选项中thing of great importance“重要的事”,thing of little value“无价值的事”,a matter of duty“责任问题”,a matter of principle“原则问题”, 选项B最接近题干意思。