An unknown simian virus recently killed off nearly half the human

Question

An unknown simian virus recently killed off nearly half the human population of a remote jungle town. Because the disease spread at an alarming rate—victims usually exhibited signs within 8 hours of exposure, and many died within 36 hours—the simian virus, if an outbreak occurs again, is likely to cause more deaths than has any other previous virus.

Which of the following pieces of information most effectively calls into question the validity of the conclusion?

(A) The Zairean strain of the Ebola virus, known as Zaire ebolavirus, has a mortality rate of nearly 75%.

(B) The village in which the outbreak of the unknown simian virus occurred is located in a country that has had several viral outbreaks in the last two decades.

(C) Viruses that have very little time to incubate before destroying their hosts tend not to lead to widespread epidemics, because quarantines are put in place before the disease can spread.

(D) The town in which the outbreak occurred had only fifty people, of whom twenty-four died.

(E) Viruses tend to be most destructive in densely populated areas, oftentimes spreading amongst thousands of people before any quarantine can be put in place.

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Bismuth83 · Answer

1. The conclusion in the text is that  "the simian virus, if an outbreak occurs again, is likely to cause more deaths than has any other previous virus" . This is based off the information that the simian virus has a high mortality rate and fast spread. Now we need to  find an argument that would most weaken the conclusion .

1.    The Zairean strain of the Ebola virus, known as Zaire ebolavirus, has a mortality rate of nearly 75%.  Here, the mortality of this virus is high, however, there is no comparison to the simian virus.    This statement doesn't work.

2.    The village in which the outbreak of the unknown simian virus occurred is located in a country that has had several viral outbreaks in the last two decades.  This is irrelevant to the conclusion.    This statement doesn't work.

3.    Viruses that have very little time to incubate before destroying their hosts tend not to lead to widespread epidemics, because quarantines are put in place before the disease can spread.  Here, this explains that the virus won't spread fast and thus won't lead to large epidemics.    This statement does weaken the conclusion.

4.    The town in which the outbreak occurred had only fifty people, of whom twenty-four died.  The argument here is trying to say that the conclusion is based off a small population and isn't valid, however, the argument is less effective than the previous one.    This statement doesn't work.

5.    Viruses tend to be most destructive in densely populated areas, oftentimes spreading amongst thousands of people before any quarantine can be put in place.  Here, the statement is somewhat strengthening the conclusion instead.    This statement doesn't work.

Krunaal · Answer

Option C. effectively calls into question the conclusion by suggesting that because the virus kills quickly and exhibits symptoms rapidly, it may not spread widely before being contained by quarantine measures. This weakens the idea that the virus could cause more deaths than any previous virus.

Answer C.

Answer C.

Nikhil17bhatt · Answer

IMO C 
To determine which piece of information most effectively calls into question the validity of the conclusion, we need to understand the conclusion and the reasoning behind it:

Conclusion
The simian virus, if an outbreak occurs again, is likely to cause more deaths than any other previous virus.

Reasoning
The virus spreads rapidly (signs within 8 hours).
It has a high mortality rate (many die within 36 hours).
Analysis of Answer Choices
(A) The Zairean strain of the Ebola virus, known as Zaire ebolavirus, has a mortality rate of nearly 75%.

This information provides a comparison of mortality rates but does not directly challenge the conclusion about the potential for widespread death caused by the simian virus.
(B) The village in which the outbreak of the unknown simian virus occurred is located in a country that has had several viral outbreaks in the last two decades.

This information provides context about the location but does not directly challenge the conclusion about the potential for widespread death caused by the simian virus.
(C) Viruses that have very little time to incubate before destroying their hosts tend not to lead to widespread epidemics, because quarantines are put in place before the disease can spread.

This information directly challenges the conclusion. It suggests that because the simian virus kills its hosts quickly, it may not spread as widely as other viruses that have longer incubation periods. This would mean that the simian virus might not cause as many deaths as other viruses that can spread more easily before being detected and quarantined.
(D) The town in which the outbreak occurred had only fifty people, of whom twenty-four died.

This information provides context about the scale of the initial outbreak but does not directly challenge the conclusion about the potential for widespread death caused by the simian virus in a larger population.
(E) Viruses tend to be most destructive in densely populated areas, oftentimes spreading amongst thousands of people before any quarantine can be put in place.

This information provides context about the conditions under which viruses can be most destructive but does not directly challenge the conclusion about the potential for widespread death caused by the simian virus.
Conclusion
The most effective piece of information that calls into question the validity of the conclusion is:

(C) Viruses that have very little time to incubate before destroying their hosts tend not to lead to widespread epidemics, because quarantines are put in place before the disease can spread.

This information directly challenges the assumption that the simian virus will cause more deaths than any other previous virus by suggesting that its rapid lethality could actually limit its spread and, consequently, its overall death toll.

prantorboni · Answer

An unknown simian virus recently killed off nearly half the human population of a remote jungle town.  Because the disease spread at an alarming rate —victims usually exhibited signs within 8 hours of exposure, and many died within 36 hours—the simian virus, if an outbreak occurs again, is likely to cause more deaths than has any other previous virus.

The rate of spread has been stated as the main cause to cause death. So, we find a way to challenge the conclusion keeping the rate of spread on mind.

Now, consider option, (C) Viruses that have very little time to incubate before destroying their hosts tend not to lead to widespread epidemics, because quarantines are put in place before the disease can spread which aligns with our presumption.

Answer: C.

Bunuel · Answer

Magoosh Official Explanation:

Answer: (C)

(A) is tempting, but the main problem with it is that it only tells us that the mortality rate is higher than that of any other virus. That doesn't mean that the Zairean strain is likely to cause a greater number of deaths! For example, let's say we have a population of 1000 people, in which 500 people got the simian virus and 50% die - that means that 250 people have died. Now let's say that 200 people get the Ebola virus and 75% die, which is only 150 people. Ebola might be less contagious and doesn't spread as fast, so even though it has a higher mortality rate, the actual death count might not be that big.

(B) does not speak to the how likely the current virus is to spread.

We learn from the paragraph that the virus has very little time to incubate before killing a person (only eight hours). (C) describes how such lethality actually prevents the virus from spreading from person to person (a quarantine is put in place before the disease can spread). Thus the virus will not cause many deaths. (C) effectively weakens the argument.

(D) is just restating information already found in the paragraph; we know the virus killed many people in the village, but that does not tell us anything about its likelihood of spreading and becoming the most lethal virus the country has seen. 24 people might not be considered a huge epidemic, but if the virus spreads to other villages it will kill more people quickly. In order to call the conclusion into question, the answer choice needs to tells us that the virus will not spread and (D) does not give us any extra information about whether it will spread or stay within the village.

(E) suggests the conclusion is valid, except for the fact that (E) is talking about how rapidly a virus can spread in densely populated areas. The village is not a densely populated area.

An unknown simian virus recently killed off nearly half the human

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An unknown simian virus recently killed off nearly half the human

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