Hi P.S.
After reading the explanations above, I'm still trying to understand why answer choice B is Necessary. My error of reasoning when completing this question during PT, is that I missed the emphasis of premise 2 of ""If cost of gas in Chester costs 2x as much in Tilsen". When breaking down the conclusion & premises here is what I solved:
Conclusion: CC gas increases at all
CC moves to T
Contrapositive of Conclusion: CC DOESN'T move to T
CC gas didn't increase at all (it stayed the same)
P1: CC gas costs 2x more than T
P2: CC cost of gas costs 2x more than T
CC move to T
Contrapositive of P2: CC DOESN'T move to T
CC costs of gas NOT 2x ore than T
I realize there's a difference between "costs increase at all" and "costs 2x more than T" doesn't mean the same thing, so I can't combine these statements to make a logical chain.
So my 1st question is, where do we get the information that we need to assume what answer choice B states (that T won't increase their gas prices)?
In Kelly's explanation she states: "
The author draws the conclusion that if the cost of natural gas increases in Tilsen at all, then CesChem will move. If the cost is exactly twice now, any increase in CesChem would make it more than twice the cost.
But, that only works if the cost in Tilsen stays the same
."
In the 1st sentence of her explanation, I'm sure she meant to say conclusion states that if cost natural gas increases in CHESTER. But what I'm not understanding is what indicates that we have to assume anything about Tilsen prices increasing or not? The conditional statements only indicate/trigger from the sufficient condition, about the costs of Chester prices compared to Tilsen (not the other way around). So where or how can we assume this?
My approach was incorrect in that, I thought there was a missing link in "energy needs". I assumed that the assumption depended on the energy needs of ChesChem. For this reason, I had contender of C and D and picked C as answer choice. After reading explanation, I realize why D isn't necessary/has relevance to the argument.
But what makes answer choice C incorrect? I thought answer C was relevant because I related gas price increasing to being profitable. Whether it was going to be profitable for ChesChem to move to T. Can someone explain where answer C goes wrong?
Any clarification will help. Thanks in advance!