若有以下程序:#include<iostream>using namespace std;class A {private: int x;public: int z; void setx(int i) {x=i; } int getx () {return x; }}:class B : public A{private: int m;public: int p; void setvalue(int a, int b, int c) {setx(a) ;z=b;m=c; } void display{) {cout<<getx ()<<", "<<z<<", "<<m<<end1; }};int main(){ B obj; obj. setvalue(2,3,4); obj.display(); return 0;} 程序运行以后的输出结果是
A.产生语法错误
B.2,3,4
C.2,2,2
D.4,3,2