Answer:
is there like a article, passage or something that comes with this answer
Answer:
at
Explanation:
It is most likely at but all of them gramatically make sense but not physically.
For example, you cannot stand in a door but the sentence is correct.
Standing on a door is quite strange but the sentence itself makes sense
Glad I was able to help you Geny :) Let me know if you need anything else
-AaronWiseIsBae
Legendary Founder Of Thebes