So dogged were Frances Perkins’ investigations of the garment industry, and her lobbying for wage and hour reform was persistent, Alfred E. Smith and Franklin D. Roosevelt recruited Perkins to work within the government, rather than as a social worker.
A.and her lobbying for wage and hour reform was persistent,
B.and lobbying for wage and hour reform was persistent, so that
C.her lobbying for wage and hour reform persistent, that
D.lobbying for wage and hour reform was so persistent,
E.so persistent her lobbying for wage and hour reform, that
正确答案是E，看前人的解释如下： so + adj. + be + sub（倒装形式）, that....= sub + be + so + adj + that....什么什么是如此的怎样怎样，以至于。。。
So dogged were Frances' investigations that Roosevelt hired her to work in govenment = Frances' investigations were so dogged that Roosevelt hired her to work in government.
So dogged were Frances' investigations, (and) so persistant (was) her lobbying （以前一部分并列的so...), that Rooselvelt hired her to work in government = Frances investigations were so dogged, and her lobby was so persistant, that Rooselvelt hired her to work in goverment.
已经解决问题了，这里贴出链接，需要的同学看看吧，应该对。