A couple of points.
I also disagree with the question's validity, but... a multiple choice test demands one to answer the question that is the most correct or closest to being correct.
(the above test question, in my opinion, HAS to be a misprint)
Gary
The resistance to earth of the rod is one thing, rarely even coming close to 25 Ohms. But that is only part of the path back to a transformer. The resistance of the earth itself is extreme high, and will most likely only permitt miliamps of current to flow. That is the reason the NEC says that earth is not permitted, not the electrical connection of the rod to the earth.
If one has a 120v or 277v circuit opening the overcurrent device during a fault, there is most likely another path (parallel path) that is "assisting" in the process.