Critical Reasoning

The U.S. gets 5 percent of its oil from Mexico. If Mexico raises the price of its oil by 20 percent, that will result in an increase of 1 percent (5 percent times 20 percent) in the price of oil products in the U.S.

Which of the following is an assumption upon which the above argument depends?
A) Oil prices in the U.S. are not affected by inflation in Mexico
B) Other countries will not increase oil exports to the U.S.
C) The price increase will not result in a decrease in the sales of Mexican oil products
D) People will not substitute other products for those made from Mexican oil
E) A 1 percent price increase in oil products will not be recognized by the buying public
[spoiler]
iut took me 1 minute and 55 seconds to choose C . i was just between B and C but was deeply thinking that B could be the answer. if the usa would import oil from another countries instead of importing oil from mexico becos of 5% increasing price, the concluion will be failed however considering another countries is far from information mentioned in the text so i didint choose B. whats your idea? whats your answer?[/spoiler]