if和whether I don't know ____ she will go tomorrow .____ she goes ,I ' ll tell you .

if和whether I don't know ____ she will go tomorrow .____ she goes ,I ' ll tell you .
I don't know ____ she will go tomorrow .____ she goes ,I ' ll tell you .
A.if ,Whether B.whether ,Whether C.if ,That D.if ,If
if和whether如何区别,这道题如何分析,请详解,