* Doubt regarding :gerunds and infinitives

[krazygmat]

1. Before the Civil War, Harriet Tubman, herself an escaped slave, returned again and again to Maryland to guide other slaves along the Underground Railroad to freedom.
(A) herself an escaped slave, returned again and again to Maryland to guide
(C) an escaped slave herself, returned again and again to Maryland for guiding

My Query:
Between the two options: why is "for guiding" incorrect: isn't this a "gerund acting as object of preposition "for".
Harriet Tubman returned to Maryland for guiding other slaves to freedom.... why is this sentence incorrect.
Thanks.

[RonPurewal]

Please cite the source (author) of this problem. We cannot reply unless a source is cited (and, if no source is cited, we will have to delete the post!). Thanks.

also, even if you only have a query about one or two of the options, the policy of this board is that you always post the entire question, including all five of the answer choices. when you return with the source of the question, please post the rest of the answer choices; thank you.