Only cadres learn legal knowledge: I am not a cadre, so I do not need to learn legal knowledge. Which of the following inferences is most similar to the above inference structure? ['As long as the exam passes, you can enter Nanjing University to study; Zhang Jing fails the exam, so Zhang Jing cannot enter Nanjing University to study.', 'If you fail the exam, you cannot enter Nanjing University to study; Zhang Jing entered Nanjing University to study, so Zhang Jing passed the exam.', 'Only after passing the exam can he enter Nanjing University; Zhang Jing fails the exam, so Zhang Jing cannot enter Nanjing University to study.', 'Only after passing the exam can he enter Nanjing University; Zhang Jing passes the exam, so Zhang Jing can enter Nanjing University to study.']