Choose the word which has the underlined part pronounced differently from the rest

Choose the word which has the underlined part pronounced differently from the rest:
1.  a.delighted   b.wished  c.stressed  d.worked  (gạch chân ed)
2.  a.health  b.thought   c.them   d.thank    (gạch chân th)
3.  a.abandon  b.bank   c.sing   d.thank   (gạch chân n)
4. a. aim   b.operation   c.day   d.international  (gạch chân a)
5.  a.calm   b.call   c.ask   d.ciass   (gạch chân a)