Calling method from base class by refrance

#include <iostream> 
#include <string> 
using namespace std; 
class person{ 
    public : 
    void introduce(){ 
        cout<<"hey from student "<<endl; 
    } 
}; 
class student : public person { 
    public : 
     void introduce(){ 
         cout<<" hey from person "<<endl; 
     } 
}; 
void WhosThis(person &p){ 
    p.introduce(); 
} 
int main() 
{

   student anil; 
   anil.introduce(); 
   WhosThis(anil); 
    return 0; 

}