Choose the word whose underlined part is pronounced differentrly from the others

choose the word whose underlined part is pronounced differentrly from the others
 1) a.head     b.hear     c.clear    d.dear
 2) a.brother  b.weather  c.through  d.than
 3) a.coffee    b.volleyball   c.chocolate    d.opposite
 4) a.teenager  c.together   c.guess   d.regular