Which of the following C++ code will give error on compilation?

[answerhappygod]

================code 1=================
#include <iostream>
using namespace std;
int main(int argc, char const *argv[])
{
cout<<"Hello World";
return 0;
}
========================================
================code 2=================
#include <iostream>
int main(int argc, char const *argv[])
{
std::cout<<"Hello World";
return 0;
}
========================================
a) Code 1 only
b) Neither code 1 nor code 2
c) Both code 1 and code 2
d) Code 2 only