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. chemical B. delicious C. especially D. musician 
2. A. machine B. chef C. check D. sugar
 3. A. generation B. question C. competition D. portion
4. A. unusual B. pleasure C. pleasant D. leisure
5. A. conversation B. discussion C. decision D. mission