单选题 有以下程序
#include＜stdio.h＞
main()
{ FILE*fp;int a[10]={1,2,3},i,n;
fp=fopen("d1.dat","w");
for(i=0;i＜3;i++) fprintf(fp,"%d",a[i]);
fprintf(fp,"/n");
fclose(fp);
fp=fopen("d1.dat","r");
fscanf(fp,"%d",&n);
fclose(fp);
printf("%d/n",n);
}
程序的运行结果是______。