Sentence Correction (SC) | What is the rule here?

Pay heed to thess senteces
1. "Why did she not go to school?"
2. "Why did not she go to school?"
3. "Why did Kamal not go to school?"
4. "Why did not Kamal go to school?"

Which two are correct and what is the rule here?

I am aware that this post not related to GMAT but I am curious to know the answer. As soon as I get the answer I will delete this post. Thankyou.

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