The quality of unrefined olive oil is not actually defined in terms of acidity, yet extensive tests have shown that the less free oleic acid an unrefined olive oil contains per liter, the higher its quality. The proportion of free oleic acid that an olive oil contains is an accurate measure of the oil’s acidity.

If the statements above are all true, which of the following conclusions is best supported by them?

A When an olive oil is refined, the concentration of oleic acid in the oil is reduced.

B The quality of an unrefined olive oil can be determined only by accurately measuring its acidity.

C If an unrefined olive oil is intermediate in acidity between two other unrefined olive oils, it will also be intermediate between them in quality.

D Free oleic acid is the only acid that unrefined live oil contains.

E People who judge the quality of unrefined oils actually judge those oils by their acidity, which the judges can taste.

参考答案是C，可我觉得A也没错啊，请哪位NN指点一下

整个段落从没提到A的情况，当然不能选。虽然现实生活中也许确实如此。

这道题从头至尾都没提过refined,典型的无关选项啊，怎么推也不可能推出来啊。原文一直在讨论the causal relationship of unrefined olive's quality and its acidity.

为什么B错呢？是不是B的 "only” 错了？