This point is made in two different statements that can be joined. Choice a is not the answer because there is no such insight. The passage states that people are born with reason and that it can be developed, so choice c is incorrect. The test in question is the LSAT, but is never mentioned that only lawyers can benefit from reasoning training, so choice d is incorrect. Choice e is just not true.

The main idea of the passage is mentioned in the first paragraph, and then reiterated and paraphrased in the third paragraph, “that training people in reasoning skills can reinforce brain circuits involved in thinking and reasoning and might even help increase a person’s IQ scores.” There is no mention of why the U.S. National Institute of Neurological Disorders and Stroke funded the study, rendering choice b incorrect. Although practicing for the LSAT is stated to change the brain, it never says it will do so chemically, making choice c false. The passage states that preparedness can NOT predict your future success, making choice d incorrect. The statement in choice e may be true, but it is sure to be subjective for each individual and would not be labeled as a main idea.

The last paragraph states “that intensive, real-life educational experience that trains reasoning also alters the brain pathways that support reasoning ability.” It is stated that improving on the LSAT after preparation is not a new idea, making choice a true. The statement of choice b is mentioned in the third to last paragraph. The passage states that brain function specific to reasoning is plastic, or malleable, through adulthood, so choice c is true. It is stated in the passage that among other things, the LSAT is reasoning training, making choice e true.