Because I got up very late this morning I was late for class. A. but B./ C. so

问题补充：

Because I got up very late this morning, I was late for class.

A. but B./ C. so

答案：

解析：考查连词的用法。前半句“因为我今天早晨起床晚了”，后半句“我上课迟到了”之间存在因果关系，故选B项。特别注意because与so不可以同时使用。