LSAT Explanation PT 34, S2, Q25: Although wood-burning stoves are more efficient

LSAT Question Stem

Which one of the following, if true, most seriously weakens the argument? 

Logical Reasoning Question Type

This is a Weaken question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

Let's begin by analyzing the argument in the passage. The argument states that wood-burning stoves are more efficient than open fireplaces, but they are also more dangerous. The reason for this is that wood-burning stoves release cooler smoke, which travels more slowly and deposits more creosote, a flammable substance that can clog a chimney or even ignite inside it. To simplify this, imagine two types of cars: one is faster but produces more pollution, while the other is slower but cleaner. The argument here is that the faster car is more dangerous due to its higher pollution rate.

The structure of the argument is as follows:

- Premise: Wood-burning stoves are more efficient than open fireplaces.

- Premise: Wood-burning stoves release cooler smoke that deposits more creosote.

- Conclusion: Wood-burning stoves are more dangerous than open fireplaces.

An "Evaluate" question for this argument could be: "Are there any other factors that contribute to the danger of wood-burning stoves or open fireplaces?"

Now, let's discuss the question type, which is a Weaken question. We are asked to find the answer choice that most seriously weakens the argument.

a) The most efficient wood-burning stoves produce less creosote than do many open fireplaces.

- This answer choice does not undermine the conclusion that wood-burning stoves are more dangerous in general. It only states that the most efficient stoves produce less creosote, but it doesn't address the overall danger comparison.

b) The amount of creosote produced depends not only on the type of flame but on how often the stove or fireplace is used.

- This answer choice does not weaken the conclusion because it doesn't provide any information about the relative danger of wood-burning stoves and open fireplaces. It only states that the amount of creosote produced is influenced by usage.

c) Open fireplaces pose more risk of severe accidents inside the home than do wood-burning stoves.

- This is the correct answer. It weakens the conclusion by introducing another factor that contributes to the danger of open fireplaces, suggesting that they may be more dangerous than wood-burning stoves in some respects.

d) Open fireplaces also produce a large amount of creosote residue.

- This answer choice does not weaken the conclusion because it does not provide a comparison between wood-burning stoves and open fireplaces. It only states that open fireplaces produce a large amount of creosote, but it doesn't say if it's more or less than wood-burning stoves.

e) Homeowners in warm climates rarely use fireplaces or wood-burning stoves.

- This answer choice is irrelevant to the argument, as it does not provide any information about the relative danger of wood-burning stoves and open fireplaces.

In conclusion, answer choice C is the correct answer because it introduces another factor that contributes to the danger of open fireplaces, suggesting that they may be more dangerous than wood-burning stoves in some respects, therefore weakening the argument.