When they write a question, they write the answer for it. Plain and simple. then they can make 3 other choices that are not quite the answer. It's not as if these questions appeared on a stone and the test writer divined the correct answer. It's the correct answer because they wrote it to be the correct answer. They made it the correct answer because it answers the question that they wrote. The "inside information" you need is the ability to think rationally.
Any of the prep courses have spent enough money analyzing the test to give you all of the help you might need if you're deficient in your thought process. There is no advantage, other than innate intelligence to understand the reasoning, you could have by being able to write the test questions.