Given the following definition for a map, which code fragment will correctly iterate through the map and output each item?

A. for (std::map::iterator itr = mymap.begin(); itr != mymap.end(); itr++)
cout << itr << " " << *itr << endl;
B. for (int i = 0; i < mymap.size; i++)
cout << i << " " << mymap[i] << endl;
C. for (auto item : mymap)
cout << item.first << " " << item.second << endl;

C. for (auto item : mymap)
cout << item.first << " " << item.second << endl;