Choose the word that has the underlined part pronounced differently

Choose the word that has the underlined part pronounced differently;
1.A.happy          b.character           C.fat             D.Classmate
2.A.teacher          B.pleasure             C.please           D.meet
3.A.character        B.christmas           C.children         D.school
4.A.tomorrow         B.brown                 C.now             D.how
5.A.slim                   b.thin                  C.smile             D.visit