#10 - A recent study suggests that Alzheimer’s disease,

[Johnclem]

Hello,
For this lovely question i just want to know if my reson for eliminating E is right. I saw E as also strengthening the argument . As it states where the casuse doesn't occur the effect doesn't occur. However I ended up eliminating it because I felt it only strengthened the premise , but it left us hanging with whether or not Jacob and alzimer are related . Since if they were not we wouldn't be able to say the virus causes alzimers.


Thanks
John

[Claire Horan]

Hi John,

I agree with you that choice (E) does strengthen the argument due to its lack of connection to Alzheimer's disease (and thus, its lack of connection to the conclusion), but an answer choice that strengthens a premise can also strengthen an argument.

I would go further and say that answer choice (E) is largely irrelevant even to the premise that Creutzfeldt-Jakob disease is caused by a virus. It doesn't provide any support one way or the other. The fact that blood from healthy rats doesn't cause Creutzfeldt-Jakob disease in other rats only shows that blood transfusions alone don't cause the disease. It doesn't show what does cause the disease. In sum, answer choice (E) is consistent with 1) Creutzfeldt-Jakob disease being caused by a virus, 2) Creutzfeldt-Jakob disease not being caused by a virus, 3) Alzheimer's disease being caused by a virus, and 4) Alzheimer's disease not being caused by a virus.

You are on the right track. Try the method I modeled of asking yourself, if this answer choice is true: What can be true? What is likely to be true? What must be true? What must be false?