Application for X1 visa

Sorry I have another question. It is something I have been confused about, to my understanding, when I apply the student X1 in my country, on the application form i can choose "1 entry valid for 3 months"? Initially i thought I had to choose the "multiple entries valid for 1 year" so that I would have a valid one year and can exit and reenter many times. But if I understand correctly now, the residence permit is actually your "real" one needed, stating the validity and you can enter as many times as you like?