we are using so many raw materials every day,which _________

we are using so many raw materials every day,which _________that they _________
A,are running out ,wil be used up B.are being run out ,wil run out
C,have run out of ,will be using up D,have run out,will run out of
选什么?为什么呢?which 引导的是非限制性定语从句,先行词是什么?that在句中起什么作用呢?做什么成分?