Which underlined sound is pronounced differently in each group

Which underlined sound is pronounced differently in each group

1. A. visit                     B. season               C. museum                D. sister

2. A. know                    B. how                   C. slow                      D. no

3. A. sandwich             B. chair                  C. school                   D. chicken

4. A. dozen                  B. front                   C. chocolate              D. brother

            5. A. study                   B. music                 C. student                  D. museum