A C object contains two sub-objects, of types A and B. Obviously, these must have different addresses since two separate objects can’t have the same address; so at most one of these can have the same address as the C object. That is why printing the pointers gives different values.
Comparing the pointers doesn’t simply compare their numeric values. Only pointers of the same type can be compared, so first one must be converted to match the other. In this case, c is converted to B*. This is exactly the same conversion used to initialise b in the first place: it adjusts the pointer value so that it points to the B sub-object rather than the C object, and the two pointers now compare equal.