assuption一题求解

wwc008love

Exports of United States wood pulp will rise considerably during this year.The reason for the rise is that the falling value of the dollar will make it cheaper for paper manufacturers in Japan and Western Europe to buy American wood pulp than to get it from any other source.
Which of the follwing is an assumption made in drawing the conclusion above?
A.  Factory output of paper products in Japan and Western Europe will incease sharply during the year
B  The quality of the wood pulp produced in the United States would be adequate for the purposes of Japanese and Western European paper manufacturers
C  aper manufacturers in Japan and Western Urope would prefer to use wood pulp produced in the United States if cost were not a factor
D  Deman for paper products made in Japan and Western Europe will not increase sharply during the year.
E Production of wood pulp by the United States companies will not increase sharply during the year.
 为啥选B不选C。C不是排除了一种其他的可能性吗

WO爱逍遥

C   削弱了  原文