The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officilas attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.
Which of the following , if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease?
(A) many new water-treatment plans have been built in the last five years
in the rural county.
(B) bottled spring water has not been consumed in significantly different
quantities by people diagnosed as having the intestinal disease, as
compared to people who did not contract the disease.
(C) because of a new diagnostic technique, many people who until this
year would have been diagnosed as having the intestinal disease are
now correctly diagnosed as suffering from intestinal ulcers.
(D) because of medical advances this year, far fewer people who contract
the intestinal disease will develop severe cases of the disease
(E) the water in the rural county was brought up to the sanitary standards
of the water in the neighboring countries ten years ago.
Answer: (C)
其他選項不管, 我想請問(C)
覺得解釋很牽強耶~~~
能否請大家幫個忙?
thanks!!