LSAT Explanation PT 37, S4, Q23: Robert: Speed limits on residential streets

LSAT Question Stem

Sheila's response depends on the presupposition that 

Logical Reasoning Question Type

This is a Necessary Assumption question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. Robert presents a premise that speed limits on residential streets in Crownsbury are routinely ignored, endangering people crossing those streets. He also notes that the city doesn't have enough police officers to patrol every street. Based on these premises, Robert concludes that the city should install speed bumps and warning signs on residential streets to slow down traffic. Sheila responds by arguing that this is a bad idea because people driving too fast can lose control of their vehicles when they hit a speed bump.

To make this more understandable, let's use a simple example. Imagine a neighborhood where drivers often speed, putting pedestrians at risk. Robert suggests installing speed bumps to slow down the cars, while Sheila argues that this could cause drivers to lose control and potentially make the situation even more dangerous.

An "Evaluate" question for this argument could be: "How effective are speed bumps in slowing down traffic without causing drivers to lose control of their vehicles?"

Now let's discuss the question type and the answer choices. This is a Necessary Assumption question, asking us to identify the presupposition that Sheila's response depends on.

a) This answer choice is out of scope because Sheila's argument does not rely on a comparison of Crownsbury to other cities.

b) This answer choice is out of scope because Robert's intent is not relevant to Sheila's argument.

c) This is the correct answer. Sheila's response assumes that even with speed bumps and warning signs in place, there would still be drivers who would not slow down to a safe speed and could lose control of their vehicles when they hit a speed bump.

d) This answer choice is too strong. Sheila's argument would still stand even if only a few of the people affected by the problem were harmed by the installation of speed bumps. The word "most" in the sentence is indeed exaggerated.

e) This answer choice is out of scope because nonresidential streets are not a concern for Sheila's argument.

In conclusion, the correct answer is C, as Sheila's response depends on the presupposition that even with speed bumps and warning signs in place, there would still be drivers who would not slow down to a safe speed.