Here we have a strengthen with necessary premise question. Remember that a premise is necessary for a conclusion if the falsity of the premise guarantees or brings about the falsity of the conclusion. First we check to see if the answer choice strengthens the passage, and then, if it does strengthen, we negate the answer choice to see if its negation makes the argument fall apart. If the answer choice does both those things then it is our correct answer.
Conclusion: the environmentalist's claim should be dismissed without further consideration.
Why? Because even though the environmentalists have argued that the proposal would interfere with bird-migration patterns, these same people have raised environmental objections to virtually every development proposal brought before the council. The argument poses that this indicated that the environmentalists aren't actually concerned for the environment, but are actually just trying to propel their antidevelopment and antiprogress agenda.
So, what would we need to know to strengthen the conclusion? Well, it would be helpful to know whether the environmentalists have been 100% sincere up till now. If so, i.e. if every proposal raised till now has been out of a sincere concern for the environment, then there would be no reason to think that this objection about the Golden Lake Development is not sincere, as well.
Answer choice (A) states: "Not every development proposal opposed in recent years by these so-called environmentalists was opposed because they believed it to pose a threat to the environment."
Does answer choice (A) strengthen? Yes.
Answer choice (A) helps illuminate the fact that not all of the environmentalists' proposals were raised by sincere worry for the environment. Therefore, this helps support the conclusion that this is just another "mask for their antidevelopment, antiprogress agenda," as opposed for a real concern for the environment.
Negation: All development proposals opposed in recent years by these so-called environmentalists were opposed because they believed that they posed a threat to the environment.
Does this negation make the argument fall apart? Yes.
If all of the previous proposals by the environmentalists were sincere, then the conclusion would no longer follow based on the evidence cited. The reason given as to why the environmentalists are not sincere is that they have raised environmental objections to virtually every development proposal brought before the council in recent years. But, if every single one of these was raised out of a concern for the environment, then this evidence does not prove that their claim should be dismissed without further consideration.
Thus, the negation of answer choice (A) makes the argument fall apart.
Hope that helps! Please let us know if you have any other questions.
ElaFebruary 26, 2020
I thought we were trying to prove that their motivation was not sincere
