A typical gasoline–powered lawn mower emits about as much air–polluting material per hour of use as does an automobil...

Jacob-R on March 12, 2019

Hi @ulino23

I’m happy to help. As always, let’s focus on the question stem. We are trying to find the answer that, if true, provides the most support for the argument. So what exactly was the argument?

We learn from the first premise that gas lawn mowers emit half as much air pollution per hour as a car. We learn from the second premise that collectively, these gas mowers “contribute significantly” to summer air pollution. And then we get a conclusion: Since electric mowers emit no air pollution, people can help reduce air pollution by choosing electric mowers over gas mowers.

The argument rests on a key assumption: the generation of the electricity that powers the electric mowers is not itself creating more air pollution than the gas mowers. Otherwise, choosing electric mowers wouldn’t help reduce air pollution, as that electricity had to come from somewhere!

And that is exactly the assumption that answer C addressed: producing the power to power the electric mowers causes less air pollution than running the gas mower for the same hour. Because taking this answer as true provides support for the argument, it is the correct answer.

I hope that helps! Please let us know if you have further questions.