So-called environmentalists have argued that the proposed Golden Lake Development would interfere with bird-migration...

Ravi July 23, 2019

@Julie-V,

Great question. Let's take a look at (A) and (B).

This question is a strengthen with a necessary
premise question, so if the negation of an answer choice wrecks the
argument, then we know that it's the correct answer choice.

(B) says, "People whose real agenda is to block development wherever
it is proposed always try to disguise their true motives."

(B)'s negation is, "People whose real agenda is to block development
wherever it is proposed do not always try to disguise their true
motives."

We are only talking about a single group of environmentalists, so we
do not need to assume anything about anti-development folks in
general. It's possible that other anti-development people could be
completely honest, and maybe these environmentalists are lying. Thus,
(B)'s negation doesn't wreck the argument, so it's out.

(A) says, "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."

(A)'s negation is, "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."

(A) looks great. If the environmentalists had honest environmental
reasons for them to oppose all of the previous development projects,
then they may have honest reasons to oppose this particular
development project. Thus, the argument is assuming that these folks
were lying about at least some of those previous projects. (A)'s
negation wrecks the argument, so (A) in its original form is the
correct answer choice.

Does this make sense? Let us know if you have any other questions!