PT18.S2.Q04 - marianna: the problem of drunk driving

yhchoi1687

http://7sage.com/lsat_explanations/lsat-18-section-2-question-04/
I got this question right, but not perfectly clear why (D) is correct.
Could you elaborate the answer choice (D) - why is it a clear-cut answer?

c.janson35

Sure! David's response would be more direct if the argument he was responding to was something like "When in an accident, drunk drivers are much more susceptible to serious injury than sober drivers because the alocohol in their system often prevents them from bracing in time to prevent injury."

Then, David's response would make sense, claiming that it is actually the opposite.

But Marianna doesn't make this claim or anything close to it. Her argument is that drunk drivers are more likely to cause an accident, so David's response is pretty irrelevant.

"Drunk drivers are more likely to cause accidents so more should be done to cut down on drinkin and driving."

Response: "Whoa! Actually, drunk drivers are less likely to get seriously hurt when they cause an accident when they are drunk than if they were to be sober."

You see how it doesn't address Marianna's underlying concern about drunk drivers causing more serious accidents in the first place?