I feel it is you rather than the boy who________for being late for the speech. [ ]

A. is to blame  

B. are to blame

C. is to be blamed  

D. are to be blamed

线圈自感系数的大小与（）无关。

A、线圈的匝数 

B、线圈的几何形状 

C、周围介质的导磁系数 

D、周围环境温度