单项选择题

有如下程序：
#include＜iostream＞
using namespace std;
class Book
public:
Book(char*t=" ")strcpy(title,t);
______
pnvate:
char title[40];
;
class Novel:public Book
public:
Novel(char*t=" "):Book(t)
char*Category()constretum"文学";
;
int main()
Book*pb;
pb=new Novel();
cout＜＜pb-＞Category();
delete pb;
retum 0;

若程序运行时输出结果是"文学"，则横线处缺失的语句是______。