Her grandpa was ill in bed_,she had to stay at home.A,so;B,since;C,so that;D,but.

题目

Her grandpa was ill in bed_,she had to stay at home.A,so;B,since;C,so that;D,but.
请分别介绍一下这四个选项,

答案

A
A是因果关系的结果
B是因果关系的原因 （Since her grandpa was ill in bed,she had to stay at home）
C一般不这么用
D转折的并列关系