Explanation

Reading the question: we review the prompt, which contains a causal argument and also a prediction. The easiest thing to do will be to strengthen and/or weaken the prediction using the most common error of causation, introducing a new, real, cause. The question is whether X really causes Y, where X is industrialization in the country and Y is an increase in oil sales.

Applying the filter: (A) doesn't even concern the relevant countries, so it's not a strengthener and may be the correct answer. Choice (B) sounds like industrialization, which would make it a mild strengthener as the cause of oil sales, and hence not the answer. Choice (C) is a mild strengthener--few restrictions will allow oil sales to grow freely. Choice (D) is a strengthener, because it will help establish that Energy Corp and not its competitors will be able to reap benefits. Choice (E) is a mild strengthener, because it suggests there is a buyer of the oil. The correct answer is (A).