一道语法题求解释

331589698

Although she had been known as an effective legislator first in the Texas Senate and (later in the United States House of Representatives,not until Barbara Jordan's participation in the hearings on the impeachment of President Richard Nixon in 1974 was she made a nationally recognizedfigure,as it was) televised nationwide.
A:          
B:later in the United States House of Representatives,Barbara Jordan did not become a nationally recognized figure in the 1971,when she participated in the hearing of impeachment of President Richard Nixon,which were

我想问下答案为什么是B，按照语法which就近指代，不能指代前面的句子啊？按道理不是应该选A吗？

331589698

which不是就近指代吗？怎么能指代前面那么远的名词？
还有原句什么地方出错了？