Find the word which has different sound in the part underlined

Find the word which has different sound in the part underlined.  

1

A. these

B. there

C. they

D. think

2

A. thing

B.earth

C. theater

D. weather

3

A. those

B. there

C. thank

D. without

4

A. healthy

B. northern

C. thirsty

D. mouth