下列程序的输出结果是( )。#include void main(){FILE *fp; int i, k=0, n=0;fp = fopen(“d1.dat”, “w”);for( i=1; i<4; i++ ) fprintf( fp, “%d”, i);fclose(fp);fp = fopen(“d1.dat”, “r”);fscanf( fp, “%d%d”, &k, &n);printf(“%d%d\n”, k, n);fclose(fp);}

A. 12
B. 1230
C. 123
D. 00