What is the correct form of “My Mustafas” in Arabic?

Today I want to make a quiz: What is the correct form of “My Mustafas” in Arabic? I admit that you usually won’t use this expression (“My Mustafas”), but nevertheless, the construction is pretty challenging. If you know the correct answer, you have definitely understood the concept of weak letters in Arabic, i.e, the tricky letters و and ي and Aleph.