Find the word whose underlined part is pronounced differently from the others

IV. Find the word whose underlined part is pronounced differently from the others.  (3pts)
1.     A.  cups                      B. rulers                        C. books                   D. students
2.     A. promised               B. closed                        C. raised               D. pleased
3.     A. combine                B. comb                         C. combat                 D. combust