PrepTest 154

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Weaken

Stimulus Summary:
A farmer tells us that the best reason to choose farmed salmon is that we're actually helping threatened wild salmon by doing do. When we eat farmed salmon, wild salmon get to stay alive and have lots of little salmon babies.

Answer Anticipation:
Since we're looking to weaken the argument, we want to focus tightly on the conclusion that the very best reason to eat farmed salmon is the benefit to wild salmon. This is a pretty standard causal weaken stimulus; we have an alleged cause-and-effect relationship, but not a lot of support for it. If we can debunk the causal relationship between more farmed salmon eaten and more wild salmon born, we can definitely weaken this argument significantly.

Answer Explanation:
Exactly as anticipated, there's a new premise here that gives us a reason to suspect that more farmed salmon eaten may not cause more wild salmon to be born. If the farmed salmon are eating up all of the small fish wild salmon would otherwise be feeding on, the wild salmon may not be benefiting at all from consumers' choice to purchase farmed salmon.

Key Takeaway:
Beware of distracting background information masquerading as a premise! Premises always provide support to one or more conclusions, so information that does not support a conclusion is rarely relevant when trying to weaken an argument. Just because it's included in the stimulus doesn't mean that it affects the argument.

Incorrect. This doesn't relate to the key causal relationship we're focusing on: eating farmed salmon causes more wild salmon. We don't actually care about the salmon quality if we're trying to weaken the conclusion that the benefit to wild salmon is the best reason to eat farmed.

Incorrect. Again, this has no effect on the key causal relationship supporting the conclusion of the argument. The first sentence of the stimulus is irrelevant to the conclusion, so we can dismiss any answer choices that are only related to that background info.

Incorrect. We're focusing only on the best reason to eat farmed salmon, and the support for that claim. So, information on the price of wild salmon can't help us. If we should choose farmed salmon for ecological reasons, that could still be true even if wild salmon was less expensive.

Incorrect. This is, again, just adding another reason to eat farmed salmon that doesn't relate to the single, best reason we're focusing on in the conclusion. It neither strengthens nor weakens the argument about the alleged ecological benefits of farmed salmon.