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( )。