下面程序的运行结果是 include class base{ protected: int a; public: base( ) {c

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