Think this way,

Rule: SC occurs, NC must occur.

NC occurs, Maybe SC occurred, maybe it didn't.

Ex. You are in LA, only if you are in USA.

Now, NC occurs, John is in the USA.

Can you conclude that John is in LA?

You can't because being in USA is NC. You don't have to be in LA to be in USA. You can be in NYC or Chicago.

Think of it this way,

If A, then B.

What would be the contrapositive?

If not B, then not A.

Why?

Because the rule states,

If sufficient conditions occur, necessary must occur. (To be a cat, you must be a mammal)

If a Necessary condition occurs, it doesn't mean sufficient occurred (it may or may not have occured). "You can be a mammal (NC) but not be a cat. (SC)"

AND if necessary doesn't occur, Sufficient CAN'T occur. "If you aren't a mammal, how can you be a cat?"

Now apply that to the example.

"Must" introduces the necessary condition.

SO it becomes...

To Qualify ----> Show characteristic

What if you don't show characteristics?

THEN you don't qualify.

Therefore it becomes...

/Show Characteristic----> /Qualify

Okay so I am getting these right but not because of the explanation JY is giving. I just seem to understand that the correct answer is NA. I don't know why wrong answers are wrong, but I know they are known. Does anyone else feel this way?

This was quick

Okay so I get the answer right and I can explain why it's right but for the past questions, I can not explain why wrong answers are wrong with details. It just feels wrong to me.

The reason why I picked B is because it's consistent with what the author said in stimulus that "hiccups experienced by MANY victims" which translates roughly to a some relationship. Therefore, B just restates part of the stimulus. Is this a reasonable explanation?

So basically, NC doesn't follow from SC???