Here is a very important lesson about Critical Reasoning:
**Do not treat the answer choices like you do the conclusions.**
It is important that we be critical of the conclusions. We wonder "Maybe this thing isn't true? I can imagine a situation in which this conclusion does not hold!" That's good--that's a key skill in Critical Reasoning.
But with *answer choices* that kind of thinking isn't actually helpful, and tends to lead to confusion. You're looking at B and saying "Wait a minute, I can imagine a world where the government is very inefficient and nongovernmental spending is better at lowering emissions but still achieving growth!" Of course that's possible!
But we're wondering what is NECESSARY FOR THIS ARGUMENT, not what IS OR ISN'T TRUE. This argument's conclusion is that GOVERNMENT SPENDING IS NECESSARY TO ACHIEVE THESE TWO GOALS. For government spending to be NECESSARY, non-government spending cannot be more efficient at these goals, because if it *were*, government spending would *not* be necessary. That situation, **whether it's actually true or not**, needs to be true for the author's conclusion to hold.
On a 'find the assumption' question, remember that your goal is "Which of these scenarios must be true for the argument to hold?" and is not "Is that necessary scenario actually, definitely true? Or can I imagine a scenario where it is *not* true?"
And more broadly, don't treat the answers in CR like you treat conclusions! You doubt conclusions--but you take answer choices and (generally) the premises to arguments at the their word!
Contropositive
DmitryFarber KarishmaB ReedArnoldMPREP GMATGuruNYI get that none of the options but B come close to the argument in question, but i am not convinced with (B) being a NA.
Conclusion:
To reduce carbon dioxide emissions without stifling economic growth --> Increases in governmental spending on research into energy technology will be
NECESSARYQuote:
(B) Increased governmental spending on research into energy technology will be more likely to reduce carbon dioxide emissions without stifling growth than will nongovernmental spending.
Negation of (B): Government spending is equally/less likely to reduce the C02 emissions than Non-Gov spending does.
Okay, so granted that ''Government spending is equally/less likely....'' but if we take other factors in consideration, we can still say that Gov spending is necessary.
Say, Non-Gov is very corrupt and inefficient, and even though Gov and Non-Gov are equally likely to reduce the emission, only Gov-spending ticks all the boxes, and hence it is the necessary one! I don't understand the comparison here, highlighting only one aspect.