一道关于同位语的问题 section 19-17

cxj

17.    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
(B) being an escaped slave herself, returned again and again to Maryland so as to guide
(C) an escaped slave herself, returned again and again to Maryland for guiding
(D) herself as an escaped slave, returned again and again to Maryland so as to be the guide of
(E) who had been herself as an escaped slave, returned again and again to Maryland for the guiding of

答案是A.
但是 C中 herself 的位置是否一定错？ return... to guide 与 return...for guiding 区别在那里？thanks a million!

lixiaoyang

c中的herself是可以的，return for doing好像不对，只有return to do