shall打头提问,用什么回答?（英语）

shall打头提问,用什么回答?（英语）
shall打头提问,用什么回答?
给个例题吧~
—Shall I tell Bob the news?
—No,you-------（填空）.I've told him already.
A.shouldn't B.wouldn't C.mustn't D.needn't
请尽快回答问题,