求解一GWD逻辑 （ 逻辑就是我一道疤）

MoneyHunter

Frobisher, a sixteenth-century English explorer, had soil samples from Canada’s Kodlunarn Island examined for gold content.  Because high gold content was reported, Elizabeth I funded two mining expeditions.  Neither expedition found any gold there.  Modern analysis of the island’s soil indicates a very low gold content.  Thus the methods used to determine the gold content of Frobisher’s samples must have been inaccurate.



Which of the following is an assumption on which the argument depends?



A. The gold content of the soil on Kodlunarn Island is much lower today than it was in the sixteenth century.

B. The two mining expeditions funded by Elizabeth I did not mine the same part of Kodlunarn Island.

C. The methods used to assess gold content of the soil samples provided by Frobisher were different from those generally used in the sixteenth century.

D. Frobisher did not have soil samples from any other Canadian island examined for gold content.

E. Gold was not added to the soil samples collected by Frobisher before the samples were examined.

最后答案E ，帮我解析解析

hzd515976083

题目的意思是说既然原来的方法跟现在的方法检测出来的结果不同，那么原来的方法就是错的。
那么首先想到的一个前提就是，两个方法检测的样本应该是相同的。否则，不同的方法检测不同的样本，孰好孰坏就没有可比性。
E项正好指出了两种方法检测的样本是相同的，即先前的样本没有认为的添加金子