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.10
B.20
C.30
D.0