C UM={1,4,6},C UN={1,2,3,6}
选项A,M∪N={1,2,3,4,6},不满足题意;
选项B,M∩N={5},不满足题意.
选项C,C U(M∪N)={1,6},满足题意;
选项D,C U(M∩N)={1,2,3,4,6},不满足题意;
故选:C.
C UM={1,4,6},C UN={1,2,3,6}
选项A,M∪N={1,2,3,4,6},不满足题意;
选项B,M∩N={5},不满足题意.
选项C,C U(M∪N)={1,6},满足题意;
选项D,C U(M∩N)={1,2,3,4,6},不满足题意;
故选:C.