The government has promised to do ______ lies in its power to ease the hardships of the victims in the flood-stricken area.
 
【正确答案】 C
【答案解析】 根据句意可知，所填词在句中应充当do的宾语，但是在从句中又要充当lies的主语，所以选项中符合条件的只有whatever。however相当于no matter how; whichever相当于no matter which; wherever相当于no matter where，均不符合句子要求。