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