mud flats shallow salt lakes fields of sagebrush piles of rocky debris
I gave my students this multiple choice question: Which feature of Great Basin National Park provides the best evidence that glaciers have moved over the landscape?

Only one answer is correct among these 4 choices:
- mud flats
- shallow salt lakes
- fields of sagebrush
- piles of rocky debris

Could you tell me which one is correct?

piles of rocky debris