Critical Reasoning

Automobile-emission standards are enforced through annual inspection. At those inspections cars are tested while idling: That is standing still with their engines running. Testing devices measure the levels of various pollutants as exhaust gases leave the tail pipe.

Which one of the following, if true, most strongly indicates that the current enforcement of automobile emission standards might be ineffective in controlling overall pollutant levels ?

A) As an emission-control technology approaches its limits, any additional gains in effectiveness become progressively more expensive.

B) The testing devices used must be re-calibrated frequently to measure pollutant levels with acceptable accuracy.

C) The adjustments needed to make a car idle cleanly make it likely that the car will emit high levels of pollutants hwen moving at highway speeds.

D) Mos car owners ask their mechanics to make sure that their cars are in compliance with emission standards

E) When emission standards are set, no allowances are made for older cars

I think it's C. The evidence is about testing on idling cars, but the conclusion asks about "overall pollution." If C is correct, then the same cars that pass the emissions test while idling will "emit high levels of pollutants when moving at highway speeds." Therefore, the standards of emissions testing as they currently exist would be ineffective at controlling pollution from cars when they aren't idling.

neoreaves wrote:Automobile-emission standards are enforced through annual inspection. At those inspections cars are tested while idling: That is standing still with their engines running. Testing devices measure the levels of various pollutants as exhaust gases leave the tail pipe.

Which one of the following, if true, most strongly indicates that the current enforcement of automobile emission standards might be ineffective in controlling overall pollutant levels ?

A) As an emission-control technology approaches its limits, any additional gains in effectiveness become progressively more expensive.

B) The testing devices used must be re-calibrated frequently to measure pollutant levels with acceptable accuracy.

C) The adjustments needed to make a car idle cleanly make it likely that the car will emit high levels of pollutants hwen moving at highway speeds.

D) Mos car owners ask their mechanics to make sure that their cars are in compliance with emission standards

E) When emission standards are set, no allowances are made for older cars

Only C indicates that the current strategy is not effective for controlling overall pollution levels.

This one was easy,,,
IMO -- C