they were going through the contents of the bag.( )she ran straight at them.A for this

题目

they were going through the contents of the bag.( )she ran straight at them.A for this
B that's because C that's why D that's so
说出为什么对与错，

答案

for this 不完整,应是for this reason
that's because 这是因为...,（他们正在翻阅包里的东西,因为她向他们直冲过去）显然不合逻辑
that's so,正是这样,相当于because they were going through the contents of the bag,(so不能用）she ran straight at them
that's why 没问题
我个人认为,cd都对,但从语感角度,会用C