下面程序的运行结果是
#include＜iostream.h＞
class base
protected:
int a;
public:
base( ) cout ＜ ＜ "0";
;
class base l: virtual base
public:
base l ( ) cout ＜ ＜"1";
;
class base 2: virtual base
public:
base2 ( ) cout ＜ ＜"2";
;
class derived: public base 1, public base2
public:
derived( ) cout ＜ ＜ "3";
;
void main( )
derive obj;
cout ＜ ＜ endl; Ａ) 0123 Ｂ) 3120 Ｃ) 0312 Ｄ) 3012