Question Type:
Explain the Discrepancy
The given:During the Gulf War, there were tons of smoky oil fires and deliberate oil spills
The expected result:Post-war measurements of oil contamination and PAH levels higher than usual.
The unexpected result:In reality, the post-war oil contamination was similar to pre-war levels. And the post-war PAH levels were as low as in temperate oil-producing areas of the Baltic Sea (it's not really clear why this is an apt comparison ... it seems to just be an example of an oil producing area that is not in a period of wartime)
What do we want the correct answer choice to do?
Either to explain why the post-war levels are as low as the pre-war and temperate non-war levels
or to explain why the pre-war and temperate non-war levels are as high as the post-war levels
(A) The question never says that the Persian Gulf area is a desert region. Another problem is that oil contamination was only brought up in reference to the Persian Gulf area pre-war vs. post-war. The temperate region is only introduced when we're talking about PAH levels.
(B) This is the opposite of what we need. If they told us that oil contam / PAH pollution dissipated more rapidly in desert regions, we could say, "Well then THAT'S why the post-war levels look like temperate non-war levels".
(C) This is closer, but we still have the problem that "desert region" was never brought up in the stimulus. Even if we allowed the assumption that Persian Gulf area = desert, this would only explain why the post-war Persian Gulf looked comparable to a Baltic temperate area. It still wouldn't explain why the post-war Persian Gulf looks comparable to the pre-war Persian Gulf (which would both be desert).
(D) This explains that the pre-war levels of contamination would actually be quite high to begin with (due to high PAH levels and massive oil dumping). During the war, "when regular oil production slowed down", we would just be replacing contamination from production/transport with contamination from smoky oil fires and deliberate oil spills. This, then, explains why post-war and pre-war levels are the same. It also allows us to explain why PAH levels post-war might resemble PAH levels near an oil-producing area in the Baltic Sea.
(E) The war may have ended before the fires and spills did "as much damage as expected", but that doesn't change the fact that there were still hundreds of fires and spills. So we would still expect the post-war measurements to be more contaminated then the pre-war measurements (this answer just tells us the post-war area wouldn't be AS extra-contaminated as we expected, but it still would be extra-contaminated).
(D) is the correct answer
95%
(hard)
47%
(02:39)
wrong 
