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

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

1.A.columnist     B.frustrated                     C.study                            D.adulthood

2.A.helpline        B.empathise                    C.embarrassed                D.depressed

3.A.tense              B.decision                       C.skill                              D.house-keeping