Carbon dioxide emissions are a concern for environmentalists

Question

Which of the following most logically completes the passage?

Carbon dioxide emissions are a concern for environmentalists, but another category, hydrofluorocarbons (or HFCs), is among the lesser-known types of greenhouse gas. A study of refrigerant gases showed that HFCs decompose into harmless compounds relatively quickly. Therefore, if HFCs were banned, the level of greenhouse gas pollution would be greatly reduced, especially since.

A. the study of HFCs found that one of the compounds into which HFCs decompose is a strong acid

B. corporations often delay compliance with bans on substances until after sanctions are in place

C. the substances used to replace HFCs are somewhat more expensive than HFCs

D. HFCs cause the atmosphere to trap heat thousands of times more per HFC particle than carbon dioxide does

E. the reason HFCs were not banned in the past is that they do not have any impact on the ozone layer

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Matthyrou · Answer

Hi, this one for me is a bit treacky, because they want to banned hfc thaugh =, it's mentionned that hfc is turning into harmless components... Never mind
we're looking for strenghten the arg: hfc banned= reduce green house gase's pollution.
a)the components is acid, but it's mentioned that components are harless (so the acid), wrong 
b) it doesn't strengthen the arg, wrong
c)it's speaking about cost, doesn't help, wrong
d)the more hfc in the atmosphere, the hottest the atmosphere, so the opposite effect is helping reduce pollution, right
e)it's a fact for the past, doen't help to conclude for the present pollution, wrong

glagad · Answer

This was a confusing question for me. The argument states that the HFCs  decompose into harmless gases quickly.

Bunuel · Answer

OFFICIAL EXPLANATION

This question has to do with a little-known type of greenhouse gas, HFC, that quickly dissolves into harmless compounds. The argument suggests that banning HFCs would "greatly reduce" greenhouse gas pollution, and the words "especially since" tell us that we are looking for an answer that supports this argument. Now let's go through each answer choice and see whether it supports the claim that banning HFCs would be particularly helpful in reducing greenhouse gas pollution.

Choice (A) contains a fact that is not clearly relevant. 
Choice (B) only states that corporations are lazy about following the rules until punishments are in place; this does not support the argument. 
Choice (C) states that alternatives to HFCs are "more expensive," which has nothing to do with levels of greenhouse gas pollution. 
Choice (D) stresses that HFCs are far more damaging to the atmosphere than even most environmentalists think, which makes it clear why banning them would be helpful. This looks like a great choice, and skimming the remaining answer choice, we see that (E) offers evidence against the argument.

The correct answer choice is (D)

Carbon dioxide emissions are a concern for environmentalists

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GMAT Critical Reasoning (CR) Questions

Carbon dioxide emissions are a concern for environmentalists

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615 to 715 in 15 Days (Ria's Strategies)

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