PT12.S4.Q16- Chlorofluorocarbons are the best possible

miriaml7

Why is E the better answer when compared to answer choice D? Would really appreciate someone's insight.

Joeyyyyy

Here is how this one clicked for me -- the stimulus specifies that chlorofluorocarbons need to be phased out because the standards are becoming more strict. The ? stem says that cars are meeting these more strict standards. Thus, we need to infer how this is possible. (E) Fills the gap, saying that something makes a contribution, therefore validating that cars meet said standards. (D) says that solvents that replace the chlorofluorocarbons will be marginally less effective. I would take a guess and say that you viewed (D) and thought that the replacement solvents will still be "effective" even if the difference was marginal. Overall though, given that the chlorofluorocarbons are the best possible solvents (according to stim), the standards are becoming even more strict, and cars have continued to meet the stricter standards means that something else must have contributed because the chlorofluorocarbons are no longer useful to them and they are phasing them out.
Hopefully that helps!

Logician

1) We're told that chlorocarbons are the BEST possible solvents for cleaning electronic sensors.

2) We're also told that chlorocarbons have contributed SIGNIFICANTLY to carmakers ability to meet legally mandated emission standards.

3) Now we are told that chlorocarbons will be phased out (no longer used) AND emission standards will become more strict.

So two important things to note here:
We're losing our best solvent for cleaning electronic car sensors while at the same time emission standards are getting stricter.

Now the stem tells us that despite these two factors, cars will continue to meet emission standards.

Based on this we can deduce that something must have come along that is currently contributing more to meeting emission standards than chlorocarbons were.

Why? because we know that chlorocarbons were meeting the previous bar, and the previous bar for emission standards was raised, yet the bar is still being met, despite the fact that chlorocarbons are being phased out.

D) "The solvents developed to replace chlorocarbons in car engines will be only marginally less effective than the chlorocarbons themselves" : there's a lot wrong with this answer choice. Firstly, we don't know that the new variable that is leading to emission standards being met is even a solvent, it could be something completely different. Second, it would have to be at least as good, if not better than chlorocarbons (seeing as the bar has been raised).

E) "Something other than the cleansers for electronic ignition sensors (i.e chlorocarbons) will make a relatively greater contribution to meeting emission standards than at present" - bingo. This tells us that despite chlorocarbons being phased out, something else has come along that helped us meet the new emission standards.

miriaml7

I definitely see where I went wrong. Thank you! @Joeyyyyy @Logician

pepperismydog

This definitely helped! Thanks!!