单项选择题
下面程序输出的结果为 #include"iostream.h” class A ｛ public: A()｛cout＜＜"CLASSA"＜＜endl;｝ ～A() ｛｝ ｝; class B:public A ｛ public: B()｛cout＜＜"CLASS B"＜＜endl;｝ ～B()｛｝ ｝; void main() ｛ A*p; p＝new B; B*q; q＝new B; ｝
A．CLASS A CLASS B CLASS B CLASS B
B．CLASS A CLASS B CLASS A CLASS B
C．CLASS A CLASS B CLASS B
D．CLASS A CLASS B