tusharsadawarte
In option
Quote:
C. Both people with a severe degree of depression and those with a mild degree of depression belonged to the same economic strata.
- the point made is that the type of population used for the study has similar characteristics, hence, only Vitamin D deficiency should be the reason for depression. Could you please explain why this option is wrong?
Notice the question in the stem: Which of the following is
required for the conclusion drawn by the researchers to hold true?
C is not a requirement for the conclusion to hold true. C makes the argument more logically sound, but it is not a requirement. If you negate C, all you get is a somewhat weaker argument.
Contrast this with D.
If D is negated (The lack of vitamin D
is triggered by depression) then the entire argument falls apart. Supplementing vitamin D would not do anything, because it is depression that causes low Vitamin D and not the other way around, as the scientists have assumed. Therefore, D is a required assumption, as the argument cannot stand without it.