Steven: The allowable blood alcohol level for drivers should be cut in

Here's the question:

Steven and Miguel's statements provide the most support for that they would disagree about the truth of which one of the following statements?

So, we need to choose the statement such that one of them agrees with it and the other doesn't.

Here's what Steven says:

Steven: The allowable blood alcohol level for drivers should be cut in half. With this reduced limit, social drinkers will be deterred from drinking and driving, resulting in significantly increased highway safety.

We see that Steven believes that, deterring social drinkers, i.e., people who have a little to drink when socializing and thus have blood alcohol levels below the current legal limit, will result in "significantly increased highway safety."

Here's what Miguel says:

Miguel: No lowering the current allowable blood alcohol level would have little effect on highway safety because it would not address the most important aspect of the drunken driving problem, which is the danger to the public posed by heavy drinkers, who often drive with a blood alcohol level of twice the current legal limit.

Notice that, at the beginning of his statement, Miguel says, "No." So, he's disagreeing with Steven right there.

Whereas Steven maintains that deterring social drinkers from drinking and driving will result in "significantly increased highway safety," Miguel disagrees, saying that that strategy "would have little effect on highway safety."

Let's go to the answer choices:

(A) Social drinkers who drink and drive pose a substantial threat to the public.

We can infer from what Steven and Miguel say that they disagree about the truth of this choice.

After all, if Steven believes that deterring social drinkers from drinking and driving will result in "significantly increased highway safety," he must believe that social drinkers who drink and drive pose a substantial threat to the public.

On the other hand, if Miguel believes that deterring social drinkers from drinking and driving "would have little effect on highway safety," then Miguel must believe that social drinkers who drink and drive do not pose a substantial threat to the public. After all, if deterring them from from drinking and driving wouldn't have much effect on safety, then what they're doing must not pose much of a threat.

So, this choice correctly answers the question.

Keep.

(B) There is a direct correlation between a driver's blood alcohol level and the driver's ability to drive safely.

Steven and Miguel don't indicate that they disagree on this point. Yes, they disagree on how much of a threat social drinkers with relatively low blood alcohol levels are, but there's no reason to believe that they disagree that people with higher blood alcohol levels are less able to drive safely than people with lower blood alcohol levels.

In other words, they disagree on the level at which blood alcohol levels present a real problem not on the effect of increasing blood alcohol levels of ability to drive safely.

Eliminate.

(C) A driver with a blood alcohol level above the current legal limit poses a substantial danger to the public.

Notice that Steven is saying that the legal limit should be reduced. So, he believes that a driver with a blood alcohol level below the current legal limit poses a substantial danger to the public. Of course if Steven believes that a driver with with a blood alcohol level below the current legal limit poses a substantial danger to the public, then it's logical that he believes that a driver with a blood alcohol level above the current legal limit also poses a substantial danger to the public

Also, we see that Miguel agrees with the idea that a driver with a blood alcohol level above the current legal limit poses a substantial danger to the public. After all, he mentions the danger posed by "heavy drinkers, who often drive with a blood alcohol level of twice the current legal limit."

So, Steven and Miguel both agree with this statement.

Eliminate.

(D) Some drivers whose blood alcohol level is lower than the current legal limit pose a danger to the public.

This is a tricky choice.

We know that Steven agrees with this choice since he says that reducing the legal limit would result in "resulting in significantly increased highway safety."

At the same time, we might think that Miguel disagrees with this choice since he says, "lowering the current allowable blood alcohol level would have little effect on highway safety."

However, the truth is that the fact that Miguel doesn't believe that, in general, drivers whose blood alcohol level is lower than the current legal limit pose a substantial danger doesn't mean that he believes that NO drivers whose blood alcohol level is lower than the current legal limit pose a danger to the public. Given what he says, it could be that he believe that at least SOME drivers whose blood alcohol level is lower than the current legal limit pose a danger to the public. Maybe he believes that a small percentage of those drivers are particularly unable to drive with even a little alcohol in their blood even though most of those drivers don't pose a substantial danger.

So, we have no reason to believe that Steven and Miguel disagree about the truth of this choice.

Eliminate.

(E) A driver with a blood alcohol level slightly greater than half the current legal limit poses no danger to the public.

We have seen that Steven and Miguel disagree regarding whether drivers with blood alcohol levels slightly greater than half the current legal limit pose a SUBSTANTIAL danger to the public, with Steven believing they do and Miguel believing they don't.

At the same time, Miguel doesn't say that he believes that drivers with a blood alcohol level slightly greater than half the current legal limit pose NO danger to the public. Maybe he believes that such drivers pose some danger, just not a substantial danger.

So, for all we know given the information we have, Steven and Miguel both agree with this choice.

Eliminate.

The correct answer is (A).