B. later in the United States House of Representatives, Barbara Jordan did not become a nationally recognized figure until 1974, when she participated in the hearings on the impeachment of President Richard Nixon, which were

C. later in the United States House of Representatives, it was not until 1974 that Barbara Jordan became a nationally recognized figure, with her participation in the hearings on the impeachment of President Richard Nixon, which was

D. then also later in the united States House of Representatives, not until 1974 did Barbara Jordan become a nationally recognized figure, as she participated in the hearings on the impeachment of President Richard Nixon, being

这个题目atina敲错了，开头的句子应该是 Although she had been known as...

对比5个选项里面的开头部分能看出then also这两个词是不必要的，原句里面没有，加上去之后then和later语义上有重复，所以这里至少可以告诉我们前半句而言ABC比DE要好。

从一致性关系上看，对于这种让步壮语从句，一般来说如果从句主语使用了代词，则该代词应该直接指代主句主语，从这个角度看C是不好的，A也是不那么好的，因为A的主语是She而BJ是在句子中的时间壮语中出现的。

再往后看能看到一些相对更为明确的理由，the hearings on the impeachment of PRN，这个词组的意思是对于尼克松的弹劾的听证会，所以后面的非限定于从句所说的被电视播出的是听证会而不是弹劾，那么应该使用的是复数（hearings而不是impeachment），所以CE是错的，并且A的it的指代也不好，这里用复数还有一个害处就是使得这个定语修饰只能修饰hearings而不会出现修饰不明确的问题。

D最后所使用的being是多余的，同时也会使修饰产生歧义

B选项是比较好的，没有上述问题，而且意思明确

希望上面的解答能帮到你