Explanation for Options B vs D :
Often in handling CR questions what you are looking for is more a best answer than an exactly right answer, and it often makes sense to keep answers until you find a better one.
In this case, B does provide a difference, but the difference that B provides is not clearly related to agricultural production. While maybe there is some story one could come up with that would tie B to agricultural production, there is no clear and direct connection between the difference
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Often in handling CR questions what you are looking for is more a best answer than an exactly right answer, and it often makes sense to keep answers until you find a better one.
In this case, B does provide a difference, but the difference that B provides is not clearly related to agricultural production. While maybe there is some story one could come up with that would tie B to agricultural production, there is no clear and direct connection between the difference
...
