Stim: Pacific water is hotter. Some say climate change, but this is FAR FROM JUSTIFIED (this is the main conclusion - the thing the author wants to argue). It could be natural climate cycles.
As you can see, the key to this is really getting down to what the main conclusion is BEFORE you go to the answers. MCs will always be that of which the author is trying to convince you. I know my answer is "the climate argument is far from justified". Now let's go get it.
(A): Nope, this is one of the premises.
(B): This takes the argument too far. The author never said it ISN'T global warming, they argue that said opinion is a long way from confirmed. We're training to be lawyers here, Details matter.
(C): Perfect. It even has that "far from justified" language we were looking for.
(D): This is the author's alternate explanation to back up their main point, but it isn't the main point itself.
Ex: "People say aliens don't exist, since we haven't seen them. But I'm telling you these people are wrong! What if aliens are already here??" The point this person is making is that the alien deniers are wrong. The 'what if' sentence is just throwing a possibility out there.
(E): This is basically B again, only this time they tried to make it sound fancier and more complicated by slapping an "If" at the front and making it conditional. Still wrong.