Correct my sentence.

My friend presents some presentation about his hometown's university. I want to ask him about what country is the number 1 to send there students to learn in your university as international students. I mean which country sends most ?

How can i ask ?

" What country does the most international students study in your university ?"

or

" What country is the most international students there ?"

or

" What country has the most international students in your university ?"

Thank you.