During the Era, humans left the continent of and spread across the globe. They were , which means they moved from place to place in search of food. They survived by tracking game and collecting plants and berries, a practice called .

The clue is that people tracked game and collected plants and berries. This way of getting food is called hunting and gathering, so choice B completes the final blank. Migration means movement from one region to another, while pastoralism involves raising and herding animals.

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