Answer:
The implementation of new automobile-efficiency standards will result in less air pollution.
Step-by-step explanation:
A is not correct because one of the purposes of these standards is that they reduce oil consumption.
B is not correct because these standards will enable the vehicles to drive more miles per gallon.
C is correct because having vehicles that spend less oil and drive larger distances with less will result in a reduction of air pollution.
D is not correct because the carbon dioxide emissions will reduce, not increase.