Find the words has a different sound

E1:Find the words has a different sound.
  1.A.house.      B.mouse.  C.shout.     Dought
   2.A.noise.       B.soil.        C.doing.    D.boil
   3.A.could.        B.our.        C.should.  D.would
    4.A.boy.          B.coin.       C.foil.        D.tower
    5.A.cow.          B.house.    C.amorfed. D.now
Giúp mk vs mk đg cần gấp