—Do you know the mission of the volunteers?—No. But I think they will end up doing there

问题补充：

—Do you know the mission of the volunteers?

—No. But I think they will end up doing there will promote public awareness of environmental protection.

A. that

B. no matter what

C. whatever

D. whether

答案：

A. that

B. no matter what

(答案→)C. whatever

D. whether

解析：考查主语从句。Whatever引导主语从句，并在句中做doing的宾语。AC两项不能做doing的宾语；no matter what不能引导主语从句。句意：我认为我们最后做的任何事情都会提高人们的环境保护意识。故C正确。