Identifying the Correct Conditional Conjunction

Hello! Let's solve this multiple-choice question where we need to find the correct conjunction to complete the sentence. Let's start by looking at the sentence structure.

The sentence begins with a blank, followed by the first clause: we understand the basic rules that Antarctica's ice sheets live by.

Now, look closely at the second part of the sentence: can we predict what will happen to them as the climate warms.

Notice that the main clause uses an inverted word order: can we predict, instead of we can predict. This inversion is a major clue.

In English grammar, when certain restrictive or negative phrases start a sentence, they trigger an inversion in the main clause. Let's check our options for such a phrase.