英国药典(93年版)规定大黄含羟基葸醌类衍生物，以大黄酸计不得少于2．5%，其英语表示法是（）

A．It contains no less than 2．5% of hydroxyanthracene derivatives,calculated asrhein．
B．It contains down to 2．5% of hydroxyanthracene derivatives,calculated asrhein．
C．It contains more than 2．5% of hydroxyanthracene derivatives,calculated asrhein．
D．It contains up to 2．5% of hydroxyanthracene derivatives,calculated asrhein．
E．It contains not less than 2．5% of hydroxyanthracene derivatives,calculated asrhein．