若有以下程序:
#include <iostream>
using namespace std;
class Base
public:
Base ( )
x=0;
int x;
;
class Derivedl : virtual public Base
public:
Derivedl ()
x=10;
;
class Derived2 : virtual public Base
public:
Derived2 ()
x=20;
;
class Derived : public Derivedl,protected Derived2 ;
int main ( )
Derived obj;
cout<<obj .x<<end1;
return 0;
该程序运行后的输出结果是 ( )。
A.20
B.30
C.10
D.0