We’ll get onto what exactly critical thinking is, but first it’s important to take a quick look at what the test is measuring.
The problem is to judge whether or not each of the proposed conclusions logically follows beyond a reasonable doubt from the information given in the paragraph.
If you think that the proposed conclusion follows beyond a reasonable doubt (even though it may not follow absolutely and necessarily), mark the statement Conclusion Follows.
If you think that the conclusion does not follow beyond a reasonable doubt from the facts given, mark the statement Conclusion Does Not Follow.
Perhaps they made a claim and failed to provide evidence to support it, or they shot down your argument for reasons that didn’t seem relevant.
If you picked up on either of these, then you might have an eye (or ear! In short, critical thinking is the activity of studying arguments, the ideas that they’re made up of, and the logic that binds them together.