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

Exercise 1. Find the word which has a different sound in the underlined part.
1. A. food B. foot C. hook D. wood
2. A. group B. should C. would D. could
3. A. fruit B. suit C. juice D. build
4. A. lose B. improve C. movie D. dove
5. A. pull B. lunar C. full D. put