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?
A. People in western Africa did not develop staple crops that they stopped cultivating once rice and yams were introduced
B. There are no plants native to western Africa that, if domesticated, could serve as staple food crops.
C. Rice and yams were grown as staple crops by the earliest agricultural societies outside of western Africa
D. Kola and okra are better suited to growing conditions in western Africa than domesticated rice and yams are
E. Kola and okra were domesticated in western Africa before rice and yams were introduced there.
after i finished the passage, My rethinking was : the conclusion "discovering when rice and yams were introduced into western Africa would establish the earliest date at which agricultural societies could have arisen there" would not be true if Western Africa have another staple corps before getting the rice and rams. so my assumption was: Western Africa didn't plant other staple plants before receiving the Rice and Yams. but i couldn't find something similar to my rethinking among the answer choices. My problem was : the way they wrote answer A is very weird so i couldn't realize that "A" is the same as my rethinking.
Answer A : "People in western Africa did not develop staple crops that they stopped cultivating once rice and yams were introduced"
i couldn't understand this phrase "that they stopped cultivating"
Any advice to how can i understand unclear answers in future ?
Thank you for your post.
When I look at your post, I see that you have tried to apply the process to solve the question. However, in your prethinking, you have missed an important point here which could have led to the difficulty that you faced.
The assumption that you identified in your prethinking is – “Western Africa didn't plant other staple plants before receiving the Rice and Yams.”.
If I interpret your statement correctly, according to you, the assumption made by the author is: “People in western Africa did not develop staple crops before rice and yams were introduced there”.
Let’s look at how you reached the above statement. If we refer to the argument, it says that rice and yam were the first known staple crops
that were grown in Africa. From this statement, the author makes a jump by saying that discovering when rice and yams were introduced into Western Africa would establish the earliest date
at which agricultural societies would have arisen there. Now first known/recorded evidence and earliest date could be two different things. So you are right that the other author is assuming that there were no other staple crops grown before the introduction of rice and yams, but how is he assuming that? What is the link he/she is making? Obviously, the author is making a link between the timing of the two event and, hence, suggesting that one could deduce the timing of one event (earliest date) from that of the other (introduction of rice and yams).
Now an important step in pre-thinking the correct assumption is thinking of scenarios in which the conclusion will not hold. Accordingly, what if one argued against the link by suggesting that there were crops that were grown before the introduction of rice and yams (this is the part that you have addressed in your assumption) but of which there is no record
(this is the part you have missed)?
If crops were grown before the introduction of rice and yams, can there be a situation where the crops were not included along with rice and yam at the time the first record was captured? Such a situation is possible if the cultivation of those crops was stopped before the first record was captured
. Under such circumstances, will the author’s argument hold? The answer is NO! Therefore, it is to guard against such a consideration that option A is so constructed: People in western Africa did not develop staple crops that they stopped cultivating
once rice and yams were introduced.
In the light of the above discussion, my advice is that you need to focus a bit more on the application of the process. You are indeed on the right path. More practice in asking yourself the right questions in the pre-thinking phase will ensure that you do not miss the right answer because of the way it’s been written.
Also, I can understand how you may have found the answer choice complex. Here, I would like to advise you to, use the concepts learned in the SC course to your benefit in CR.
What we prescribe in our SC course will really help you understand such long/complex sentences. Break down complex statements in to segments/clauses. The option statement in this case says: “People in western Africa did not develop staple crops that they stopped cultivating once rice and yams were introduced”. Breaking it into segments, we get:
1. People in western Africa did not develop staple crops
2. that (refers back to the staple crops in the first clause) they stopped cultivating once rice and yams were introduced
So in the above sentence basically says that those people did not develop some type of staple crops. What type of staple crops are these? These are staple crops whose cultivation was stopped once rice and yams were introduced there. Hence, this statement basically guards the author’s argument against a possible counter.
Hope the above discussion helps!
| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com