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Agricultural societies cannot exist without staple crops. Several food plants, such as kola and okra, are known to have been domesticated in western Africa, but they are all supplemental, not staple, foods. All the recorded staple crops grown in western Africa were introduced from elsewhere, beginning, at some unknown date, with rice and yams. Therefore, discovering when rice and yams were introduced into western Africa would establish the earliest date at which agricultural societies could have arisen there.
Which of the following is an assumption on which the argument depends?
People in western Africa did not develop staple crops that they stopped cultivating once rice and yams were introduced
There are no plants native to western Africa that, if domesticated, could serve as staple food crops.
Rice and yams were grown as staple crops by the earliest agricultural societies outside of western Africa.
Kola and okra are better suited to growing conditions in western Africa than domesticated rice and yams are.
Kola and okra were domesticated in western Africa before rice and yams were introduced there.
Option A is the right answer.
Question type: Find the assumption question.
Summary of the argument: If you discover the date when rice and yam was introduced then we know
earliest date when agricultural societies were introduced.
A) Correct Answer
B) This doesn’t talk about the dates.
C) We are not worried about societies outside western Africa.
D) This doesn’t talk anything about the date.
E) This weakens the argument by saying that there was something earlier than rice and yams.