nothing..i'm busy..see

i'm busy now,ask him to see me _other_time I'm fuckin' busy! I’m very busy I'm busy on weekdays ,so I can come to see you ( )on Sunday( I'm busy today.Can i go to see you t__? I'm not busy.I have( )to do.括号中填什么?A.nothing B.something C.a -I'm busy now.Could you come back___time?-Ok.see you later. I'm nothing I‘m nothing to Actually I'm nothing. I see all,but I am nothing I'm really very busy