Choose the word (A, B, C or D) whose underlined part is pronounced differently

choose the word (A, B, C or D) whose underlined part is pronounced differently
1. A.lamps                B sinks            C.sofas
2. A.full                     B.lunch            C.sun                 D.study
3. A.brother              B.homework          C.mother          D. son
4. A.cat                     B.father                C.calm              D.family