ChatGPT does not do a great job on logical reasoning questions.

we're not being asked to think about what strengthens an argument in this question, just what the main conclusion of it is.

You're allowed to bring in outside information in a Strengthen/Weaken question type (technically) because the correct answer choice is trying to either strengthen or weaken the stimulus. This wouldn't be the case for something like a Must Be True question where the task asked of you from the stem is different and you can't take in outside information because your basis for the correct answer choice is limited to the information in the stimulus. The issue with E being the incorrect answer has to do with the fact that some people doing well in school outside of the program has nothing to do about the strength of the program itself and your task is to weaken the conclusion that we should expand the program (or whatever, can't remember exactly what it was). B is correct because if the parents in the program are past educators then that could be the alternative reasoning as to why they did well in the program, not the program being a good program itself.