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

I. Choose the word which has the underlined part pronounced differently from the others.
1.
chemistry
study
primary
deny
2.
change
orchestra
coach
chicken
3.
horrible
hour
hundred
hold
4.
bark
vanilla
leopard
cinnamon
5.
would
where
well
who
GIÚP MÌNH VỚI NHÉ!