Question from the C++ - Fundamentals test

What does the following code return ?

class A {
public:
void f() {cout << "A";}
};

class B {
public:
void f() {cout << "B";}
};

class C : public A, public B {
public:
void g() {f();}
};

int main() {
    C c;
    c.g();
    return 0;
}