有以下程序

#include <stdio.h>

main()

{ FILE *fp; int a[10]={1,2,3},i,n;

fp=fopen("dl.dat","w");

for(i=0;i<3;i++) fprintf(fp,"%d",a[i]);

fprintf(fp,"\n");

fclose(fp);

fp=fopen("dl.dat","r");

fscanf(fp,"%d",&n);

fclose(fp);

printf("%d\n",n);

}

程序的运行结果是

A)12300

B) 123

C) 1

D) 321