有以下程序
#include＜stdio.h＞
main()
FILE *fp;int i=20,j=30,k,n;
fp=fopen("d1.dat","w");
fprintf(fp,"%d\n",i);fprintf(fp,"%d\n",j);
fclose(fp)；
fp=fopen("d1.dat","r");
fscanf(fp,"%d%d",&k,&n);printf("%d%d\n",k,n);
fclose(fp);
程序运行后的输出结果是( )。
A．20 30
B．20 50
C．30 50
D．30 20
