How did the Great Rift Valley impact human settlement?

The finding and processing of food was very important to our human ancestors. It isn’t surprising that they made tools to help them with this task. Gona, in the Great Rift Valley of Ethiopia, is the earliest known stone tool site. It is littered with artifacts of 2.6-million-year-old tools. The tools found at Gona were crude, sharp objects.

Explanation:

the answer is c.

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