单项选择题

若有以下程序:
#include <iostream>
using namespace std;
classA

private:
int a;
public:
void seta(int x)

a=x;

void showa()

cout<<a<<",";

;
class B

private:
int b;
public:
void setb(int x)

b=x;

void showb()

cout<<b<<",";

;
class C:public A,private B

private:
int c;
public:
void setc(int x,int y,int z)

c=z;
seta(x);
setb(y);

void showc()

showa();
showb();
cout<<c<<endl;

;
int main()

C c;
c.setc(1,2,3);
c.showc();
return 0;

程序执行后的输出结果是( )。

A.1,2,3
B.1,1,1
C.2,2,2
D.3,3,3