Country W has banned importation of oranges from Country V

[B BTGmoderatorLU]

Source: Princeton Review

Country W has banned importation of oranges from Country V in order to protect Country W's orange growers. Since orange prices in Country W have risen since this ban was instituted, the ban is considered a success.

Which of the following, if true, would cast doubt on the conclusion above?

A) The demand for oranges in Country V has risen.
B) The demand for oranges in Country W has decreased.
C) A freeze in Country V damaged large portions of the orange crop.
D) The rise in Country W's orange prices will lead to a decline in sales of those oranges.
E) Orange growers no longer need to spend advertising money to convince consumers Country W produces superior oranges to Country V.

The OA is D

[D deloitte247]

To know what cast the doubt, we need to find what will make the ban unsuccessful.
Premises: To protect orange growers in country W, importation of oranges from country V was banned.
Conclusion: The ban is considered a success since orange prices in country W have risen.
Explanation: orange growers in country W could not sell at a good price due to the importation from country V.

Option A - Incorrect
This does not affect the ban. The conclusion is not about country V but country W.

Option B - Incorrect
In as much as it does not change the rise in price of the oranges, it also does not cast any doubt to the conclusion.

Option C - Incorrect
The conclusion is not concerned about country V.

Option D - Correct
This causes a doubt because the conclusion given in the argument is the cause to the decline in sales of the oranges.

Option E - Incorrect
This is outside the scope of the argument