单项选择题
有如下程序: #include 〈iostream〉 using namespace std; class Base { private: char c; public: Base(char n) :c(n) {} ~Base ( ) { cout〈〈c; } }; class Derived : public Base { private: char c; public: Derived(char n) :Base(n+1),c(n) { } ~Derived () { cout〈〈c; } }; int main ( ) { Derived obj (’x’); return 0; } 执行上面的程序将输出( )。
A.xy
B.yx
C.x
D.y