A.if (a) printf("%d/n",x);else printf("%d/n",y);
B.if(a==0) printf("%d/n",y);else printf("%d/n",x);
C.if(a!=0)printf("%d/n",x);else printf("%d/n",y);
D.if(a= =0)printf("%d/n",x);else printf("%d/n",y);