Please, explain this question to me.

[mariselaclovis]

P: Washingtonia filifera is one of many pine tree species, but it is the only one that is indigenous to California.

(A): (A plant should be cultured in a state if that plant is indigenous to that state.) MY ANSWER

(A): (A plant should be cultured in a state if and only if that plant is indigenous to that state.) THE RIGHT ANSWER

C: Some pine trees should not be cultured in California.

Thank you.

Michela

[christine.defenbaugh]

Thanks for posting, mariselaclovis!

Remember that on we are looking for the assumption that will bridge the gap between the premise and the conclusion.

PREMISES:
1) WF is a pine species indigenous to CA
2) many other pine species are NOT indigenous to CA
CONCLUSION:
Some pines should NOT be cultivated in CA

In order to bridge this gap, we need something that will tell us that certain pines should *not* be cultivated in California. The correct answer does exactly that! Let's break it down:

A plant should be cultured in a state if and only if that plant is indigenous to that state.

If this rule were true, then what would that tell us about all those pine species not indigenous to California? Since they can only be cultured where they are indigenous, they should *not* be cultured in California! That gets us right to our conclusion, that some pine trees shouldn't be cultivated there.

The incorrect answer only tells us that IF a pine species is indigenous to a place, that it should be cultivated there. That would mean that the Washingtonia filifera should be cultivated in California, but it doesn't tell us that any of the species shouldn't be cultivated there. All those other species that are indigenous to other places should be cultivated in those other places, for sure, but this answer would not prevent them from *also* being cultivated in California. Thus, we would not be able to conclude that there are some pine trees that shouldn't be cultivated in California.

I hope this helps clear things up a bit!