NandishSS wrote:
In response to drought conditions, the city of Valhalla banned the use of water hoses to push leaves, sticks, and other yard debris off of pavement into storm drains. However, the use of such water hoses had the other benefit of pushing dust and ash down the storm drains, as well, and public health officials fear that more dust and ash particles in the air will decrease air quality and lead to respiratory illnesses. Therefore, Valhalla should lift the ban.
Which of the following is an assumption required by the argument?
(A)The respiratory illnesses that could result from increased dust and ash particles in the air are severe enough to be life-threatening.
(B)Most of the dust and ash particles in the air result from those particles being blown off of pavement.
(C)There are no methods other than the use of water hoses for removing dust and ash particles from pavement.
(D)The drought in Valhalla is not yet severe enough to require the rationing of water.
(E)The drought in Valhalla has increased the amount of dust and ash particles on the city's pavement.
VERITAS PREP OFFICIAL SOLUTION:
For those who don't anticipate the answer to this question (why not just vacuum up the dust? why does it have to be done with a hose?), the Assumption Negation Technique is helpful here. If you take the opposite of the correct answer to an assumption question, it will directly weaken the argument. If it doesn't, then that answer is incorrect.
If you negate these answers:
(A) would then say that the illnesses from dust are NOT severe enough to be life-threatening. But does that weaken the argument? This still allows for plenty of hardship to the community and good reason to remove the dust and ash.
(B) would then say that less than half the dust and ash comes from pavement. But think about if 40% of the dust and ash were indeed from pavement: wouldn't removing that from the air be a major benefit?
(C) would say that there are other ways to get rid of the ash and dust (like a vacuum or broom). If so, then there is no need to reverse the hose policy! You can still remove the harmful particles while protecting against further drought.
(D) would say that the drought conditions are severe enough to ration water. But this still leaves you weighing the public health issue of dust in the air versus limiting car washes, lawn care, showers, etc. (anything that might be rationed), so this doesn't directly attack the conclusion.
And (E) would say that the drought has not increased the amount of dust on the pavement. But as long as there was always harmful dust on the pavement, it's still a good idea to remove it, so (E) is not a necessary assumption.
Choice (C) is correct.In option C, we need to make a lot of assumptions like how effectively the plans can be implemented or there are no side effects/flaws in comparison to the water hoses that can release the dust particles.
In option B- if the majority of the dust particles are from pavement, then uplifting the ban can help as less dust partciles will be there in the air effecting the air quality.