Although exposure to asbestos is the primary cause for mesothelioma, a slow-developing cancer, researchers believe that infection by the SV40 virus is a contributing case, since in the US 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Researchers hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.
Which of the following, if true, most strongly supports the researchers' hypothesis?
A) SV40 is widely used as a research toll in cancer laboratories.
B) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40
C) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.
D) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.
E) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40
How did you eliminate C? And why is E the answer?
Other posts on MGMAT forum and this forum say that C states something we already know. I disagree.
the reasoning is:
Yes, we know vaccine was contaminated. But whether it could have an effect 40-50 years down the line is not known. So, knowing that those vaccine still have traces of SV40 gives a subtle new information that the virus can actually survive 40-50 years. So, it strengthens the hypotheses.
vaccine was contaminated with virus SV40 in 1960 ---> (Virus is still present in those vaccine samples of 1960 i.e. virus can survive 40-50 years) ---> vaccine is the source of virus found in cancer tissue.
To make things clear I tried to form an analogy:
David answers a question today. 50 years ago, David read a book that had the answer. The quiz master hypothesizes that reading that book helped David answer the question today.
Now, if we have to strengthen this hypothesis and 2 options are:
1. In a recent interview David mentioned that he remembers what he had read in that book.
2. Tom who never read the book, could not answer the question.
which one of the option would one choose?
David - Polio vaccine of US
Tom - Polio vaccine of Finland
Reading the book - contamination by virus
answering the question in quiz - virus in mesotheliomas
mentioned that he remembers - still show traces
"Choose to chance the rapids and dance the tides"