I'm sorry, but the sentence is not valid with either proposition. It should start "Our teacher ... ". You will find 'each' a useful word in building your sentence.
Avoid passive constructions unless they are essential. Here you have all the information necessary for an active mode sentence.
Ah, Thank you all for your kind explanations. I really appreciate it!
But I got a important question.
Someone said like this. As you see, he said "for us" is correct. What is your opinion?
His explanation is confusing.
One doughnut was allowed *us / for us by our teacher. vs
(These sound awkward!)
DIRECT OBJECT AS SUBJECT
If the direct object is selected, a prepositional phrase is formed for the passive clause (not the active clause) with the addition of either to or for. (These sound awkward!)
A question was asked us (X) / to us (X)/ of us¹(0) by our teacher.
Some time was saved *me/ for me by my friend.
One doughnut was allowed *us / for us by our teacher.