The sentence needs commas because the participial phrase is essential.
Answer:
so that they could better understand the diagnosis of ASD and for people who have it...
I am here to tell you that you should absolutely do the work yourself and that there is no way in tarnation that you should use any essay-writing services on the Internet, then translate it to Chinese then back to English. You need to just write it yourself and not do what I just said not to do.
The answer to that question is C.