单选题 有以下程序#include<stdio.h>#include<string.h>void main(){char w[20], a[5][10]={"abcdef", "ghijkl", "mnopq", "rstuv", "wxyz."};int i;for (i=0;i<5;i++)w[i]=a[i][strlen(a[i])/2];w[5]='\0';puts(w);}程序的运行结果是______