以下程序,哪个是不正确的? A) int main(){ class A { int v; }; A a; a.v = 3; return 0; } B) int main() { class A { public: int v; A * p; }; A a; a.p = & a; return 0; } C)int main() { class A { public: int v; }; A * p = new A; p->v = 4; delete p; return 0; } D) int main() { class A { public: int v; A * p; }; A a; a.p = new A; delete a.p; return 0; }