Scientists analyzing air bubbles that had been trapped in Antarctic ice during the Earth's last ice age found that th...

Ravi on June 5, 2019

@msaber,

Happy to help.

We're looking to weaken the scientist's hypothesis. With causal
arguments, the missing piece between the premises and the conclusion
of the argument is that the correlation does not definitively imply
causation. It's possible there's an alternative cause for the effect,
or maybe the argument is confusing the cause and effect with one
another. In the correct answer, we know that we need to see an
alternative cause, cause without an effect, or effect without a cause
in the answer choice. The correct answer choice will be the one that
makes the argument's conclusion less likely.

(D) says, "Sediment from the ocean floor near Antarctica reflects no
increase, during the last ice age, in the rate at which the shells
that diatoms leave when they die accumulated."

(D) is capturing effect without a cause. The effect (the increase in
carbon dioxide) occurred, but the cause (the increase in algae)
didn't. This undermines the scientist's hypothesis, so it's the
correct answer.

Hope this helps. Let us know if you have any more questions!