有以下程序
#include
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