Selena: Asteroid impact on the Earth caused the extinction of the dinosaurs by raising vast clouds of dust, thus b...

liwenong28 on November 26, 2020

Hi

I am not an instructor but let me try to explain how I got the correct answer. I saw this as a Strengthen with Necessary premise question and Trent's conclusion is "So the extinctions must have been due not to asteroid impact on the Earth but to some other kind of cause".

The correct answer (E) states that "no more than one large asteroid struck the Earth during the period when the dinosaurs were becoming extinct". Using the negation test if you negate (E) it will state:

"more that one large asteroid struck the Earth during the period when the dinosaurs were becoming extinct". If that is the case, his conclusion falls apart because there is a possibility that the dust from more than one asteroid caused enough dust for the dinosaurs to extinct.

I hope the above helps!