Psychologist: We measured the "cognitive plasticity," or the willingness to accept new ideas, of a group of people of both genders and of all ages. The first-born children in the study consistently exhibited less cognitive plasticity than did their siblings. It is reasonable to think that those who are open to new first-born children will tend to be more adventurous than will the first-borns.
What this question is testing
Conclusion
Later-born siblings are the adventurous ones in the family — more likely to take risks and explore than their cautious, tradition-bound older siblings.
Evidence
The study found that first-borns are less willing to accept new ideas than their younger siblings. The psychologist then takes a leap: being open to new ideas probably means being adventurous in general.
Assumption
The psychologist measured one thing (willingness to consider new ideas) and predicted another (adventurous behavior). That is like measuring how much someone likes trying new restaurants and concluding they would probably go skydiving. It is "reasonable to think" the two go together, but reasonable speculation is not evidence. The argument needs something to nail down that connection.
Goal
Find the answer that provides actual evidence — not just wishful thinking — that people who are open to new ideas also tend to be adventurous in their actions.
Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.