IMO Answer should be D.
If an option proves that the cause and effect are irreversible than that option strengthens the argument or can be the assumption of the argument.

Archit

Emotional stress is a well known cause of certain serious health problems, including high blood pressure and cardiac complications. Now, an additional concern can be added to the list of maladies caused by emotional stress. A recent study surveyed both people who have high levels of emotional stress and people who don’t, and found that people with high emotional stress levels are significantly more obese and nervous than people with lower levels of emotional stress.
Emotional problems--> many other effects (two of them- obesity, nervousness).
Point to observe--> obesity and nervousness are the effects of emotional stress not the other way round
Way to solve a causal relationship i.e if Cause(C)-->Effect(E) --> Then the correct answer must be one of
i)If C is there then E must be there.
ii)If E occurs then C must be there.
iii)E should not in turn cause C


Which of the following is an assumption on which the argument rests?

A) Obesity and nervousness can lead to serious health problems.It is saying that E is causing C, a serious mistake
B) Emotionally stressed out people are aware of the various health problems attributed to emotional stress, including high blood pressure and cardiac complications. out of scope, cause and effect relations must be answered using above techniques only.
C) Equivalent numbers of people with high and low levels of emotional stress were surveyed for the study. noway concerned with the number
D) Obesity and nervousness do not make individuals less capable to deal with emotionally stressful situations. saying that E Does not in turn cause C, point (iii) in our discussion, therefore right
E) Emotionally stressed out people who had encountered an emotionally stressful situation immediately before responding to the survey were more obese and nervous than the people form same group who had not encountered any emotionally stressful situation for a few days. saying that E caused C, in other words people who were obese responded as being stressed

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Nice explanations everyone, I have updated the question with OA
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Here goes the OE. Suggestions to improve the quality of OE are most welcome

The argument shows a causal relationship between the premises and the conclusion. The conclusion states that emotional stress causes people to become obese and nervous. The assumption in this causal argument should must support the causal direction of the conclusion. i.e. the assumption must prove that A causes B or Emotional stress causes obesity and nervousness.

The assumptions in a causal arguments are often of two types:

i) Assumptions that support the causality of the argument either by eliminating an alternate cause of the conclusion OR
ii) by demonstrating that the conclusion, it it exists, is in proper direction. In other words A is caused by B and not B has caused A.

Any option which does not tell us anything about the causal link between Emotional eating and, obesity and nervousness can be safely eliminated.

A) Obesity and nervousness can lead to serious health problems.

The stimulus does not discuss the seriousness of health problems, so, this choice becomes irrelevant. Moreover, no link to the causal relationship

B) Emotionally stressed out people are aware of the various health problems attributed to emotional stress, including high blood pressure and cardiac complications.

Again the awareness of people on problems related to emotional stress is irrelevant.

C) Equivalent numbers of people with high and low levels of emotional stress were surveyed for the study.

The number of respondents does not say anything about the causal link between emotional eating and, obesity and nervousness.

D) Obesity and nervousness do not make individuals less capable to deal with emotionally stressful situations.

This answer choice rules out an opposite direction for the causality, making our conclusion valid. Thus, the correct choice.

E) Emotionally stressed out people who had encountered an emotionally stressful situation immediately before responding to the survey were more obese and nervous than the people form same group who had not encountered any emotionally stressful situation for a few days.

This choice is incorrect for two reasons. First, the argument never compares some emotional eater to other emotional eaters. Second, the argument is not based on immediate impact of emotional stress in making people obese and nervous.



Vercules
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