In the past year

[BTGmoderatorDC]

In the past year, Harborville has had an unusually high rate of new cases of a certain disease. An investigation revealed that over the past five years Harborville's public water supply has had a high level of pollutants. Medical researchers have hypothesized that Harborville's water is reposnsible for the high rate of new cases of the disease.

Each of the following provides additional support for the researcher's hypothesis EXCEPT:

A. Most of the people afflicted with new cases of the disease had regularly drunk larger quantities of Harborville's water than had other Harborville residents.
B. The same types of pollutants that have been found in Harborville's water have been independently linked to occurrences in other towns of the high rates of this disease.
C. Some of the people with newly diagnosed cases of this disease began to develop the disease before Harborville's water became polluted.
D. The rate of new cases of diseases among Harborville's residents who get their water from private sources is not unusually high.
E. Towns with geographic and demographic characteristics similar to those of Harborville, but without polluted water do not have a high rate of the disease.

Can some experts explain the best option?

OA C

[ErikaPrepScholar]

We want to find the answer that does NOT support the researchers' hypothesis. Looking back at the passage, we see that researchers have hypothesized that Harborville's water is responsible for the high rate of new cases of the disease. So any answer that supports the idea that Harborville's water --> disease can be eliminated.

A. This means that people who got the disease drank more Harborville water than people who didn't get the disease. This means that drinking more Harborville water is likely tied to the disease. This SUPPORTS the hypothesis. Eliminate.
B. If the pollutants in Harborville's water are tied to the disease, the Harborville's water is likely also tied to the disease. This SUPPORTS the hypothesis. Eliminate.
C. If people started to get sick before Harborville's water became polluted, this means that the polluted water is likely not the case of the disease. This WEAKENS the hypothesis. This must be our answer.
D. This tells us that people who don't drink Harborville water are less likely to get the disease than other people in the town (who do drink Harborville water). This SUPPORTS the hypothesis. Eliminate.
E. This tells us that geographic and demographic factors are not causing the disease. This SUPPORTS the hypothesis. Eliminate.