Choose the word whose underlined part pronounced differently from the other

Choose the word whose underlined part pronounced differently from the othrs
1:     A.egg.        B.less .  C.repair
2:     A.fine.        B.animal . C.chicken
3:     A.rack.       B.snack.    C.many.    D.class
4:     A.student.   B.shelf.      C.left.      D.help