PT8.S4.Q21 - For the claim that the concern

wkim2015

Hi everyone! can someone explain why the answer is (a)? I can't figure out at all why this is (a). I really appreciate the help. Thank you so much!

FixedDice

Relevant premise: Environmentalists have opposed all developmental proposals.
Relevant conclusion: Environmental concern is not the environmentalists' real concern.

For the conclusion to be true, one must assume that the environmentalists have at least one other reason (i.e. the agenda mentioned in the second sentence) for opposing development.

If you negate (A), you get: All developmental proposals opposed by the environmentalists were opposed because they believed those proposals would threaten the environment. In other words, the environmentalists opposed all developmental proposals because they were genuinely concerned about the environment. That weakens the argument, and therefore (A) is the correct answer.