class point { public: I }; // CONSTRUCTOR point (double initial_x = 0.0, double initial y = 0.0); // MODIFICATION MEMBER FUNCTIONS // CONSTANT MEMBER FUNCTIONS point operator+ (double &in) const; private: friend point operator+ (double &lhs, point& rhs); double x; // x coordinate of this point double y; // y coordinate of this point Which line is invalid? Explain why. 1. point myPointl, myPoint2; 2. double shift = 8.5; 3. myPointl = shift + myPoint2; 4. myPointl.operator+(shift); 5. myPoint1 = myPointl + shift; How would you fix the problem?