Choose the word underlined part is pronounced differently from the other

choose the word underlined part is pronounced differently from the other 

1. a.pottery  b.collect  c.melody  d.monopoly  (o)

2. a.h(ea)rd    b.b(i)rd      c.w(o)rld  d.pict(u)re    

3. a.bird - wat(ch)ing        b(.ch)ildren   c.s(ch)ool  d.(ch)allenge