有下面程序段：
#include "stdio.h"
#include "string.h"
main()
char a[3][ 20]="china", "isa", "bigcountry!";
char k[100]=0, *p=k;
int i;
for(i=0; i＜3; i++)
p=strcat(p, a[i]);
i=strlen(p);
printf("%d\n", i);
则程序段的输出结果是

A) typedef struct
int n; char c; REC;
REC t1, t2;
B) struct REC;
int n; char c; ;
REC t1, t2;
C) typedef struct REC;
int n=0; char c='A'; t1, t2;
D) struct
int n; char c; REC;
REC t1, t2;

A) 数组元素a[5]的值
B) 数组元素a[5]的地址
C) 数组元素a[6]的地址
D) 数组元素a[0]的值加上5