TOEFL Listening: ETS-TOEFL听力机经 - 3YQ93094ROI9G083P$

Under what circumstances might it be difficult to decide how to classify a group of hunters? A. If they use tools both for hunting animals and for gathering wild plants B. If they exchange the meat they acquire for cultivated crops C. If they grow their own crops in addition to hunting animals D. If they get the majority of their food from wild plants that they gather