Dear instructor Ron:
Sorry to open this old thread.
your explanation about why option D is wrong is that
(d) falls into the "WHICH" family of modifiers.
the modifiers in that family generally refer to the noun that immediately precedes the comma.
we've seen some exceptions to this rule, in which these modifiers refer to a noun phrase of the form "noun1 + preposition + noun2" (see here post31162.html#p31162), but we've never seen this rule extended to the form above, which is "noun1 + preposition + noun2 + preposition + noun3". therefore, i think you can take it as a pretty solid rule that "which" can never stand for such a thing.
However I find out that the example you cited
https://www.manhattanprep.com/gmat/foru ... tml#p31162 just violate the grammar you mentioned .
In the example,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 televised nationwide.
which refer to hearings.
However " hearings
on the impeachment
of President Richard Nixon, " the form is noun1+preposition+noun2+preposition+noun3" ,which can refer to the noun1. And it is the correct answer.
WHY.
Thanks advanced!
JustinCKN.