Canadian mining company Bre-X had soil samples from its Busang project examined for gold content in 1992. The positive news of gold being present attracted a range of investors - from unsophisticated individuals to saavy mining professionals - to invest in the Busang project. After years of successful promotion, the truth about this worthless property slowly emerged early in 1997 and drove Bre-X stock prices nearly to zero. A repeat analysis of the soil in 1997 indicated very low gold content. Thus the methods used to determine the gold content in 1992 must have been inaccurate.
Which of the following is an assumption on which the argument depends?
(A) The gold content of the soil in Busang was much lower in 1997 than it was in 1992.
(B) After 1992, Bre-X was not mining in the same areas of Busang that the sample was taken from.
(C) The methods used to assess gold content of the soil samples in 1992 were different from those generally used during that time.
(D) Bre-X did not have soil samples from any other Busang property examined for gold content.
(E) Gold was not added to the soil samples collected by Bre-X before the samples were examined.
Conclusion: Thus the methods used to determine the gold content in 1992 must have been inaccurate.
Premise: Conflicting predictions of gold content in 1992 and 1997
Pre-thinking: The author is strongly blaming the Method to be inaccurate
. So anything in the answer choices which helps us support that the METHOD is the only one which is INACCURATE and not anything else affecting the protocol would be the correct answer
A- if the gold content was lower in 1997 than in 1992-it supports the fact the method was accurate in estimating gold in 1992
B- If they were no mining in the same area, it does not affect the conclusion of methods being inaccurate
C- If the methods were different, again the methods could have different sensitivity ranges to estimate gold content and still being accurate in its own ways
D- Even if there were soil samples not analyzed from different Busang properties, it cannot verify the accuracies of any method
E- Now, if the Gold was not added to the soil samples before estimation in 1992, it gives support to the fact that it was the method and nothing in the protocol which led to inaccurate results.
negating E- gold was ADDED to the soil sample destroys the conclusion that it was the addition of gold prior to the analysis which led to inaccurate results and not the method per say!
Waiting official explanation from Gmat-pill