Only 3) could scale but then those exam takers not using AI would fail unless they are geniuses in many areas. 1) and 2) can't be done when you have 50-70% of your course consisting of online students (Stanford mixes on-campus with CGOE external students who take the exams off-campus), who are important for your revenue. Proctoring won't work either as one could have two computers, one for the exam, one for the cheating (done for interviews all the time now).