His doctor reassured him that the new medicine was（）of poisonous

His doctor reassured him that the new medicine was（）of poisonous components.
A、released
B、cleansed
C、relieved
D、cleaned
【正确答案】：B
【题目解析】：本题考查动词辨析。release：释放，发泄。release sb from 免除职责。cleanse：v. 清洗，清理。be cleansed of 使免除，净化。relieve：减轻。relieve sb of sth：帮助减轻负担。clean：打扫，变干净 。由题干可知动词后面的宾语是有害成分，故B选项“净化”最符合题意。句意：他的医生向他保证这种新药已清除了有毒成分。