28）阅读下列程序段,则程序的输出结果为 #include "stdio.h" #define M(X,Y)(X)*(Y) #define N(X,Y)(X)/(Y) main() { int a=5,b=6,c=8,k; k=N(M(a,B,C); printf("%d\n",k); (A)3 (B)5 (C)6 (D)8