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

Since there is no proper antecedent(possessive form of noun cannot be an antecedent) for the pronoun "her", you can eliminate Choices A,C and E.
Choic D: Using this option you cannot connecct the remaining part of the sentance in a meaningful way and hence B is the right answer.

Where did you get this question? Is this OG? I choose C; however, it is apparent that is incorrect. Although, E to me makes no sense?

How is this a correct construction? So dogged were Frances Perkins' investigations of the garment industry, so persistent that her lobbying for wage and hour reform.

It looks and sounds absolutely ridiculous. What is this the 18th century version of the GMAT?

Wouldn't C be properly referencing her investigations of the garment industry? What is incorrect about C?

Ron I know you slightly touched on this as I googled the question; however, there was no full explanation. This kind of goes back to my concerns about that DS question. :X

Thanks
-BP

The OA employs ELLIPSIS: the omission of words whose presence is understood.
I posted an explanation here:

https://www.beatthegmat.com/parallelism- ... 96011.html