单项选择题

有如下程序: #include<iostream> using namespace std; class A { public: A(){cout<<"A’;} ~A(){cout<<"~A";} }; class B:public A { A*p; public: B(){cout<<"B";p=new A();} ~B(){cout<<"~B";delete p;} }; int main() { B obj; return 0; } 执行这个程序的输出结果是

A.BAA~A~B~A
B.ABA~B~A~A
C.BAA~B~A~A
D.ABA~A~B~A