--- Mary’s got crazy and has been sent to the mental hospital. Did you tell her boss about that?

--- Yes, but I _____ her husband first.

A．should have told

B．shouldn’t have told

C．must have told

D．needn’t have told

若某投资者以5000元/吨的价格买入1手大豆期货合约，为了防止损失，立即下达1份止损单，价格定于4980元/吨，则下列操作合理的有( )。

A．当该合约市场价格下跌到4960元/吨时，下达1份止损单，价格定于4970元/吨

B．当该合约市场价格上涨到5010元/吨时，下达1份止损单，价格定于4920元/吨

C．当该合约市场价格上涨到5030元/吨时，下达1份止损单，价格定于5020元/吨

D．当该合约市场价格下跌到4980元/吨时，立即将该合约卖出