有以下程序#include <iostream>using namespace std;class Complexpublic: Complex(double r=0,double i=0):re(r),im(i) double real() const return re; double imag() const return im; Complex operator+(Complex c) const return Complex(re+c.re,im+c.im);private: double re,im;;int main() Complex a =Complex(1,1)+ Complex(5); cout<<
A.real()<<’+’<<a.imag()<<’i’<<end1;
retura 0;
A. 6+6iB. 6+1iC. 1+6iD. 1+1i