有以下程序#includemain(){FILE *fp;int i=20,j=30,k,n;fp=fopen("D1v.dat","w");fprin

有以下程序 #include＜stdio.h＞ main() {FILE *fp;int i=20,j=30,k,n; fp=fopen("D1v.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

A