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

Exercise 1: Find the word which has a different sound in the part underlined.
1. A. volunteer B. engineer C. committee D. clear
2. A. population B. volunteer C. offer D. provide
3. A. tutor B. volunteer C. computer D. community
4. A. certain B. compare C. encourage D. community
5. A. charity B. chemistry C. chemical D. mechanic