Here we have a strengthen with necessary premise question. Remember that a premise is necessary for a conclusion if the falsity of the premise guarantees or brings about the falsity of the conclusion. First we check to see if the answer choice strengthens the passage, and then, if it does strengthen, we negate the answer choice to see if its negation makes the argument fall apart. If the answer choice does both those things then it is our correct answer.
Conclusion: cancer-patient support groups, may indeed have genuine therapeutic value
Why? Research has shown that a weakened immune system increases vulnerability to cancer and it is clear that participation in such groups reduces participants' stress levels.
What's the issue here? We have no idea how a weakened immune system relates to stress.
Let's look at answer choice (C): "Stress can weaken the immune system."
Does this strengthen? Yes.
If stress can weaken the immune system, and a weakened immune system increases vulnerability to cancer, something that wards off stress, i.e. participation in these cancer-patient support groups, could have a genuine therapeutic value.
Negation: Stress does not weaken the immune system.
Does the negation make the argument fall apart? Yes.
If stress does not weaken the immune system, then there is no relationship between stress and a weakened immune system, thus we do not necessarily have evidence that shows these cancer-patient support groups may have genuine therapeutic value.
Hope that helps! Please let us know if you have any other questions.
Julie-VAugust 20, 2019
(E) was a hard choice for me to eliminate, could you explain why it would be incorrect? Thanks!
