PTF97.S1.Q20 - In North America there has been an explosion...

k1000apr

I don't understand why B is the right answer. I chose E. Could someone #help me?

AllDeerWearFear

In regards to why E is wrong, someone has already posted an in-depth response in the forums so I'll just paste it below:

"Like the other incorrect ACs, E is incorrect because it isn't a necessary assumption the reasoning in the stimulus relies upon. In other words, the reasoning in the stimulus could be sound even if E was not the case.

For NA questions, we're looking for what we would normally think of as weak answers. The wrong ACs might strengthen the argument in the stimulus, or even be sufficient to justify the argument's reasoning, but none of them will provide a necessary condition for the argument. If all the wrong ACs are false, the argument may not be as strong as possible, but it won't be completely undermined. In contrast, the right AC is the only one that is absolutely necessary: if we take it away, the argument falls apart. It won't do much to strengthen, but its presence is crucial to the argument.

Imagine a world where E is false. This means that at least one of the 45 most recently established opera companies was not established as a result of enthusiasm on the part of a potential audience. By itself, that wouldn't be enough to totally undermine the stimulus; 44 of the opera companies could still have been founded because of audience enthusiasm, and the stimulus' reasoning would still hold up.

I hope this clarifies the reasoning in this question! And just let me know if you have any further questions." - Alexandra Nash

As for why B is correct, we can imagine a world in which the assumption is not true and see what follows. Suppose there were 45 or more professional opera companies that had been active 30 years ago and that ceased operations during the last 30 years. If that were the case, then the fact that 45 of the 70 professional operas companies currently active in North America were founded over the last 3 decades would not constitute evidence of an explosion of public interest in North America. At best we conclude that interest had stayed the same since the 45 companies which had closed were replaced by the more recent 45 companies and if there were more than 45 companies active 30 years ago which had ceased operations then it would be more reasonable to conclude that perhaps public interest has declined!

Answer B precludes the possibility that there were, say, 100 opera companies 30 years ago vs the 70 active now - which we need in order for the argument not to fall apart.