A. class B { public: void Func(A* pa); }

B. class B { A* mpA; }

C. class B { public: B(A* pa):mpA(pa){ } private: A * mpA; }

D. class B { public: B( ):mpA(nullptr){ } ~B( ){ } bool CreateA(int n) { mpA=new A(n); } bool KillA( ) { delete mpA; } private: A * mpA; }