请问 最后输出什么

#include<iostream>
using namespace std;


class b
{    
public:
    static int i;
    b(){ i=5; }
};
int b::i(4);

int main(int argc, wchar_t* argv[])
{
    b b1;
    cout<<"b::i="<<b::i<<endl;
    getchar();
    return 0;
}

答案
A b::i=5
B b::i=4